Five male speakers produced the vowels of Greek at slow and fast tempo, in lexically stressed and unstressed syllables, and in lexically stressed syllables of words appearing in focus position. Duration, fundamental frequency (F₀), amplitude, and the frequencies of the first (F₁) and second formant (F₂) were measured. The effects on these variables of the phonemic category of the vowel, tempo, stress, and focus were examined. The results indicated that the vowel system of Greek follows universal tendencies in terms of duration but not in terms of F₀ and amplitude. Vowels in focus position, when plotted by their F₁ and F₂ frequencies, defined a vowel space larger than that defined by vowels in any other condition.

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A thin film aluminum-air battery has been constructed using a commercial grade Al-6061 plate as anode electrode, an air-breathing carbon cloth carrying an electrocatalyst as cathode electrode, and a thin porous paper soaked with aqueous KOH as electrolyte. This type of battery demonstrates a promising behavior under ambient conditions of 20 °C temperature and around 40% humidity. It presents good electric characteristics when plain nanoparticulate carbon (carbon black) is used as electrocatalyst but it is highly improved when MnO2 particles are mixed with carbon black. Thus, the open-circuit voltage was 1.35 V, the short-circuit current density 50 mA cm−2, and the maximum power density 20 mW cm−2 in the absence of MnO2 and increased to 1.45 V, 60 mA cm−2, and 28 mW cm−2, respectively, in the presence of MnO2. The corresponding maximum energy yield during battery discharge was 4.9 mWh cm−2 in the absence of MnO2 and increased to 5.5 mWh cm−2 in the presence of MnO2. In the second case, battery discharge lasted longer under the same discharge conditions. The superiority of the MnO2-containing electrocatalyst is justified by electrode electrochemical characterization data demonstrating reduction reactions at higher potential and charge transfer with much smaller resistance.

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