Electrochemical impedance experiments were carried out in order to study the influence of the ZrO2 inorganic incorporation on the proton conductivity of sulfonated poly(ether ether ketone) (sPEEK) membranes. The impedance data was fitted to an extension of Randles' circuit, within the inorganic content and temperature ranges considered. The model fits quite well for ZrO2 loads up to 10 wt.%. Such a model allows...
In order to study the influence of the proton exchange membrane thickness on the direct methanol fuel cell (DMFC) performance, sulfortated poly (ether ether ketone) (sPEEK) membranes with a sulfonation degree (SD) of 42% and thicknesses of 25, 40, and 55 pm were prepared, characterized, and tested in a DMFC. These polymeric membranes were tested in a DMFC at several temperatures by evaluating the current-voltag...
BACKGROUND: The aim of this study was to estimate the incidence, main causes, and risk factors of iatrogenic disease occurring in a department of internal medicine. METHODS: Over a 1-year period, physicians systematically filled out a 2-page questionnaire for all patients admitted to the ward. A database was created and the data were statistically analyzed. Patients undergoing immunosuppressive, chemo-, or rad...
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