1,721,115 research outputs found
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
Studies on the Constituents of Gliricidia sepium (Leguminosae) Leaves and Roots: Isolation and Structure Elucidation of New Triterpenoid Saponins and Aromatic Compounds
No full textAbstract: Our research program on the Central American fooder plant Gliricidia sepium led to the discovery of two new triterpene saponins (1 and 2) and known aromatic compounds. The new compounds possess 3β,21β,24-trihydroxy-22-oxoolean-12-ene as an aglycon. The oligosaccharide moiety linked to C-3 of the aglycon contained two pyranoses (glucuronic acid and xylose); in addition the glucose residue of both 1 and 2 is also linked to C-21. Structure elucidation of these new compounds through the extensive use of 1D and 2D NMR techniques have provided detailed information about the sapogenin and the saccharide chains, inclusive of sugar sequence and the position of glycosylation
Studies on the constituents of Cyclanthera pedata fruits: isolation and structure elucidation of new triterpenoid saponins
No full textThe isolation of nine triterpenoid saponins (1-9), among them six new natural compounds (1-6), from the MeOH extract of the fruits of Cyclanthera pedata is reported. All of the structures were elucidated by spectroscopic methods, including the concerted application of one-dimensional H-1-H-1 total correlation spectroscopy, H-1-H-1 nuclear Overhauser effect spectroscopy), and C-13-C-13; DEPT-NMR and two-dimensional NMR techniques (double-quantum filtered correlated spectroscopy, rotating-frame Overhauser enhancement spectroscopy, heteronuclear single quantum coherence, and heteronuclear multiple bond correlation). A comparative study of seeds and fruits has been also carried out
Strumenti digitali per l’efficientamento energetico degli edifici. Una revisione sistematica della letteratura // Digital Tools for Buildings’ Energy Efficiency: a Systematic Review
No full textThe relations between the ecological and the anthropic systems can be influenced by the technological scenario which, changing, could loosen some constraints. Constraints like energy consumptions’ final accounting in the Architecture, Engineering and Construction sector (AEC) which may be replaced by estimation and subsequently real-time control of what is going to be consumed. New technologies like Building Information Modeling (BIM) and the Internet of Things (IoT) can perfectly perform these functions. BIM is designed to improve efficiency in design and construction and is used in these phases of the building’s life cycle, while IoT technologies implemented in a sensor network monitor an asset and improve efficiency, allowing predictive operations. In first instance, this is the case of Building Management System (BMS) and then of Digital Twin (DT). Through a literature-based approach, this paper examines the state of the art in the field of digital tools for buildings’ energy efficiency and the bibliographical impact of DT between them. The review method follows the PRISMA guidelines, collecting contributions from the SCOPUS databases. Results show that the majority of contributions about the theme remain anchored to the concept of BIM generally detached from the Operations & Maintenance (O&M) life cycle of buildings. Tightening the circle then, the most in-point texts come out to be just those that deal with O&M but none of them exploiting DTs. The term never appears strongly in the phases of the review suggesting that this tool is not so related to energy efficiency purposes yet. To prove the potentiality of DT in energy efficiency and in particular in O&M ones, in which BIM cannot contribute to reach the target, becomes crucial
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