1,721,331 research outputs found
PERFLUORODIACYL PEROXIDE AS POLYMERIZATION INITIATOR
No full textPROBLEM TO BE SOLVED: To provide a polymerization initiator stable against hydrolysis when used in an aqueous solvent. SOLUTION: The purpose is achieved by a perfluorodiacyl peroxide shown bellow: it has a structure expressed by the formula (wherein, when Rf is F, Rf ', and Rf" are each a 1-3C linear or branched perfluoroalkyl group); and its thermal decomposition constant Kd (sec ) in the presence of water does not differ substantially from that in the absence of water
Design study of plasma targets for laser driven wakefield acceleration experiments
Full text linkIn this work, a characterisation conducted in the SPARC_LAB (LNF-INFN) laboratories on some plasma targets, i.e. different nozzle geometries and different types of capillaries, is presented. The main goal of the work is the study and the realisation of the plasma guiding process of a laser pulse, inside a plasma-filled capillary discharge. This technique is necessary to increase the acceleration length and thus the energy gain of the accelerated beam, in the external-injection scheme of the Laser Wake Field Acceleration (LWFA). Plasma density is a characteristic of fundamental importance as it determines both the guiding and the acceleration process. Two different methods of plasma density measurement, interferometric and spectroscopic, are therefore reported. Preliminary studies of new techniques for the diagnostics of plasma inside channels and new schemes for the delivery/extraction of laser pulses inside capillaries are proposed. All topics covered include theoretical study, one-dimensional and/or fluid-dynamic simulations, and experimental data
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
Process for preparing hydrofluoroethers
No full textThe present invention relates to a catalytic process for preparing hydrofluoroethers (HFE) in high yields and
selectivity. More specifically the present invention relates to hydrofluoroethers having one end group of the -O-Rh type
wherein Rh is a saturated or unsaturated hydrocarbon group
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
Perfluorodiacylperoxides as polymerization initiators
No full textPerfluorodiacylperoxides having the following structures: wherein: when Rf is F, Rf', Rf'' are both -CF3; when Rf is -CF3, Rf', Rf'' are C1-C3 linear or branched perfluoro-oxyalkyl groups; said perfluorodiacylperoxides being such as to meet the following proviso: the thermal decomposition constants Kd (sec) in the presence of water do not undergo substantial variations with respect to the thermal decomposition constants in absence of water
α-Branched-perfluorodiacyl peroxides: preparation and characterization. J. Fluorine Chem.
No full textAppropriate 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
Le fognature dell’Ospedale Maggiore di Milano: un dibattito di igiene pubblica nella Milano di fine Ottocento
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