1,720,990 research outputs found
Corrosion of carbon steel in natural waters. Effect of oxygen and bicarbonate/carbon dioxide
No full textThe corrosive behavior of waters with different O content of 0.5-8 mg/L was detd. on mild steel specimens in a closed hydraulic circuit by the linear polarization resistance and impedance detns. Water compns. were fixed to differentiate the effect on corrosion rate of both the CO2 and HCO3-contents. The corrosion rate as function of O2 content shows 3 different behaviors. The corrosion rate increases with O2 contents 0-3 mg/L and is nearly const. with O2 from 4 to 8 mg/L, while there is a narrow range where the corrosion rate abruptly decreases. The corrosion rate for any O2 content, was more effected by the [HCO3-] than by {CO2}. An interpretation of these effects is given
Moderni metodi elettrochimici per la misura della corrosivit� dei terreni.
No full textLa nota presenta una breve sintesi sui moderni metodi, principalmente elettrochimici, per la misura della corrosività dei terreni.
Vengono descritti tecniche sia in dc (rilievo delle curve di polarizzazione e della resistenza di polarizzazione) che in ac (impedenza elettrochimica)
Steel corrosion rate in soils by a.c. and d.c. electrochemical methods
No full textMeasurements of soil specific corrosivity were performed on bare steel in clay and sand at 15% moisture content (m.c). Polarization resistance (Rp) was measured by either the potentiodynamic linear polarization method or a.c. impedance techniques. The values obtained by the former method were corrected from IR ohmic drop contribution of the electrolyte resistance (Rs) deduced from a.c.impedance measurements, whereas, to avoid the effect of electrode processes with large relaxation time, proper sweep rates were chosen. A method to evaluate Rp by a.c. impedance technique is proposed which generally gives results close to d.c. Rp measurements. Impedance data allow also some interpretation of corrosion rate determining process. © 1990
L’Oralità sulla scena. Adattamenti e transcodificazioni del racconto orale al linguaggio del teatro, Napoli, Orientale University Press (VOLUME)
No full text
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
Soil corrosivity determination by electrochemical methods
No full textMeasurements of soil specific corrosivity were performed on bare steel in clay and sand (15-35% moisture content).
Rp was obtained either from potentiokinetic linear polarization method and impedance technique. The values of the former method were corrected of IR deduced from the ac technique.
A method to evaluate Rp from impedance technique is proposed which generally gives results close to dc method.
The results indicate that corrosion process is largely conditionated by the moisture content in the clay and very scarcely in the sand.
Impedance data allow some interpretation of rate corrosion determining process
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
