1,720,961 research outputs found
A multimethod approach to study humic compounds and metal speciation in marine sediment samples.
No full textA multi-method experiment was carried out to study humic compounds and metal speciation in a marine sediment sample. The humic and fulvic acid structures were investigated by infrared spectrometry,13 C NMR, thermogravimetry, and elemental analyses. Trace metals (Cu, Pb, Cd, Zn, Fe, Cr, Ni, Co, Mn and Al) were determined in digests of the sample and in solutions obtained by selective extraction procedures. The distribution of metals associated with humic substances has also been investigated by high pressure liquid chromatography using inductively coupled plasma atomic emission spectrometer as detector.
The results show that manganese, iron and aluminum are present in inorganic form, whereas 37% of nickel and 8.8% of copper are present in the metal-humic compound form
Heavy metals in Ligurian Sea sediments: distribution of Cr, Cu, Ni, and Mn in superficial sediments.
No full textStudi elettroanalitici e reazioni chimiche accoppiate a processi elettrodici in tiocianati alcalini fusi.
No full textAnodic stripping voltammetric determination of the contamination of seawater samples by cadmium, lead and copper during filtration and storage.
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
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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