1,721,031 research outputs found
Sviluppo endofitico di Biscognauxia (= Hypoxylon) mediterranea in relazione a stress idrico e defogliazione da insetti in giovani piante di cerro. In A. Franceschini, F. Marras (eds.): L' endofitismo di funghi e batteri patogeni in piante arboree e arbustive. Sassari, Tempio Pausania
No full textInteraction of rimsulfuron with smectites
No full textThe adsorption of the sulfonylurea herbicide rimsulfuron, [N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-pyridinesulfonamide], on clay minerals with different saturating cations was studied. Three smectites with different lattice charge distribution (hectorite, montmorillonite and nontronite) were selected and made homoionic to Ca2+, Cu2+ and Al3+. Because of the instability of rimsulfuron in water, the experiments were carried out in chloroform solution. The interaction mechanism depends on the nature of the saturating cation and the tetrahedral layer charge of the silicate. Among the exchangeable ions studied, only Al3+ is able to produce degradation of the herbicide to N-(4,6-dimethoxypyrimidin-2-yl)-N-[(3-(ethylsulfonyl)-2-pyridinyl]urea. In this case, the lower the tetrahedral charge, the more active the degradation. The Ca2+-saturated clays are ineffective in the degradation. In contrast, the formation of a stable chelate complex with the saturating ion permits rimsulfuron to be adsorbed to a rather high extent into Cu(II)-clays and to be stable against degradation
Optical design of the single-detector planetary stereo camera for the BepiColombo European Space Agency mission to Mercury
No full textWe present the catadioptric optical design solution for the stereo channel of the imaging system
SIMBIOSYS for the BepiColombo European Space Agency mission to Mercury. The main scientific objectives
of the instrument are the three-dimensional global mapping of the entire surface of Mercury in
the panchromatic band and imaging of selected areas in four broad colored bands; both tasks have to be
accomplished with a scale factor of 50mper pixel at periherm. The system consists of an original compact
layout in which the two stereo subchannels share a common detector; also, the optical components are
common to the two subchannels, with the exception of the first element, which is a rhomboid prism. The
field of view of each subchannel is about 5° × 5° with a scale factor of 23 arcsec/pixel. The ray-tracing
simulation of the system shows that the design guarantees optimal aberration balancing over the entire
field of view and the entire wavelength range covered by the instrument, with ensquared energy of the
order of 80% in one pixel
Qualitative effects of the addition of withered grapes to a freshly produced red wine: the traditional governo all'uso toscano practice
Full text linkBackground and Aims: Governo all'uso toscano (GUT) is a traditional winemaking practice where withered grapes are added to a freshly fermented wine. This results in a second alcoholic fermentation and a distinctive wine, in which there is renewed interest. Grape withering is problematic for winemakers, however, both in terms of cost and risks. It is therefore important to determine the minimum amount of withered grapes needed to typify the wine in order to minimise risks and costs. Methods and Results: During the trials, Sangiovese grapes were withered for 2 months in a dedicated room, a ‘fruttaio’, with a resulting mass loss of about 40%. Afterwards, withered grapes (5–20% berry mass/wine mass) were added to a Control wine to reproduce the GUT procedure. The GUT technique significantly changed the chemical profile of the wines. Ethanol, colour intensity and hue increased, while acidity decreased. Malolactic fermentation occurred simultaneously with the second alcoholic fermentation in all GUT wines, but not in the Control wines. The GUT practice significantly changed the volatile profile, including the concentration of several primary grape compounds, such as aromatic alcohols, C6 compounds and terpenoids, and of several fermentation compounds. Conclusion: Under the experimental conditions, the optimal amount of withered grapes added to the base wine was 5%. Significance of the Study: The study described the oenological effects of GUT and the optimisation of the amount of withered grapes required to make a wine with this characteristic winemaking practice clearly recognisable
Adsorption and degradation of rimsulfuron on Al hectorite
No full textA study was carried out to examine the interactions between a smectite (hectorite) saturated with Al3+ and a sulfonylurea herbicide, rimsulfuron [N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-pyridinesulfonamide]. As rimsulfuron is extremely unstable in water, to evaluate the role of the clay surface in decomposing the herbicide, the experiments were carried out in chloroform solution. The coordination of the C=O group is initially involved in the adsorption as revealed by FT-IR analysis. The adsorbed rimsulfuron decomposes initially into N-(4,6 dimethoxypyrimidin-2-yl)-N-((3-(ethylsulfonyl)-2-pyridinyl)urea (metabolite 367). This metabolite is adsorbed onto a clay surface by coordination of the C=O group-and protonation of the pyrimidine ring. Successively, this metabolite decomposes on a clay surface to N-[(3-ethylsulfonyl)-2-pyridinyl]-4,6-dimethoxy-2-pyrimidineamine (metabolite 324). This second metabolite remains adsorbed by protonation of its pyrimidine ring
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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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