1,721,000 research outputs found
Conduction mechanism and flicker noise in zinc oxide varistors
No full textJournal of Applied Physics (1), - Measurements were performed on the power spectral density Sv of the flicker noise in ZnO varistors as a function of temperature (from 110 to 370 K), bias voltage (from 10 to 90% of the varistor voltage), and frequency (from 0.1 Hz to 2 kHz). Capacitance-voltage (C-V) curves and current-voltage (I-V) characteristics as a function of temperature were also measured. The picture resulting from these measurements is very self-consistent when the data are interpreted on the basis of a Schottky emission model and flicker island models. In particular, the temperature and frequency dependences of Sv provide direct experimental evidence of the thermally activated emission of electrons from localized states, distributed over a large spectrum of energy levels, at the ZnO grain boundaries. Both I-V, C-V curves and Sv data enable one to obtain reliable information on the intergranular barrier height, its dependence on temperature and bias voltag
Futurismo, arti decorative e quotidianità: l’eredità modernista e l’oggetto come veicolo di modernità
No full textAnalisi del rapporto fra futurismo e arti decorative, con particolare focus sull'eredità modernist
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Excess noise and its temperature dependence in thick-film (cermet) resistors
No full textMeasurements have been made of the current noise in thick-film resistors (TFR) based on Ru-pyrochlore conductive grains, with sheet resistivities covering a range of four decades. The temperature dependence of the exponent (alfa) in 1/f noise spectra and the relative integral noise was investigated in the temperature range from 77 to 650 K. It shown that the presence of a minimum in the realtive voltage noise fluctuations os a general phenomenon, as is the increase in (alfa) with increasing temperature. Tevetheless these two effects seem not be mutually correlated. The possibility of developing interpretative model for noise phenomenon in TFR is discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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