141,820 research outputs found
Logica, linguaggio e metodo in pedagogia
No full textPurtroppo capita ancóra di leggere che la pedagogia è l’arte di educare i bambini, oppure di sentir confondere il pedagogo (dell’antichità classica) con il pedagogista contemporaneo. Questo disordine generalizzato circa il vero significato della pedagogia – unito a un’opera di “depedagogizzazione” della società (a cui l’editoria e i media non sono certo estranei) – ha prodotto e continua a provocare dei malintesi sempre più diffusi a proposito del senso stesso da assegnare a queste tre parole: formazione, educazione, istruzione. Sicché esse vengono usate spesso a sproposito, senza sapere che sono invece i tre “oggetti” di studio della Pedagogia Generale intesa quale scienza umana. Il libro di Mario Gennari e Giancarla Sola – entrambi Professori nell’Università degli Studi di Genova – costruisce i capisaldi di questa antica e nobile disciplina: (a) chiarendone i paradossi, (b) fornendone una cognizione epistemologica, (c) ricostruendone la logica interna e il linguaggio, (d) affrontando la questione metodologica della ricerca scientifica e la sua operatività nelle pratiche
Melting of Iron under Earth's Core Conditions from Diffusion Monte Carlo Free Energy Calculations
No full textThe temperature of Earth's core is a parameter of critical importance to model the thermal structure of Earth. Since the core is mainly made of iron, with a solid liquid boundary (the inner core boundary) at 1220 km from the center of the Earth, the melting temperature of iron at the pressure of the ICB provides constraints on the temperature of the core. These constraints are based either on extrapolations to ICB pressure of experimental measurements, or on theoretical calculations which employed various flavors of quantum mechanics, most notably density functional theory. Significant disagreement between estimates obtained with different methods calls for calculations based on more accurate techniques. Here we used quantum Monte Carlo techniques to compute the free energies of solid and liquid iron at ICB conditions. We obtained an iron melting temperature at 330 GPa of 6900 +/- 400 K
Emerging Research in Conductive Materials for Fused Filament Fabrication: A Critical Review
No full textThe progress of Industry 4.0 and the advancement of robotic design are revealing a significant gap in the capabilities of current manufacturing techniques and the selection of materials that are available in electronics. Present-day electrical systems largely rely on metals, but there is a driving need to develop new electrically conductive objects with a wide range of material properties, including expanded flexibility and softness, and with increasingly complex geometries. Electrically conductive composites can replace traditional metal-based systems. In particular, thermoplastic composites become electrically conductive with the incorporation of conductive fillers or polymers while retaining to a large extent the processability of the thermoplastic matrix. This is where fused filament fabrication (FFF), an additive manufacturing (AM) technique capable of processing a variety of thermoplastic-matrix feedstock materials, can be leveraged to create electrically conductive objects with new functionalities. While there is an increasing number of publications describing the FFF of electrical objects such as sensors and circuits, there is no comprehensive review outlining the functioning mechanisms, drawbacks, and advantages of FFF as applied to conductive materials. The present review fills this lacuna by offering a critical analysis of the specific challenges and solutions to promote FFF of electrically conductive polymers and composites
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
posata per utilizzo con una sola mano
No full textPosata per utilizzo con una sola mano che comprende due leve fulcrate tra di loro. Queste leve definiscono due bracci di potenza contraposti atti ad essere impugnati dalla mano del utilizzatore e due bracci di resistenza contrapposti, provisti di rispettive lame per tagliare il cibo tra esse
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Genetic divergence and phylogenetic inferences in five species of Mugilidae (Pisces : Perciformes)
No full textAllozyme electrophoresis was used to compare the genetic divergence of global populations of Mugil cephalus Linnaeus, 1758 and two congeneric [M. curema Cuvier & Valenciennes, 1836; M. gyrans (Jordan & Gilbert, 1855)] and two more distantly related [Liza ramada (Risso, 1826); Xenomugil thoburni (Jordan & Starks, 1896)] species on the basis of LS enzyme loci. The amount of genetic divergence among the species examined is in agreement with their present systematic status, the differences being larger among non-congeneric species than among species of the same genus. Intraspecific genetic distances in M. cephalus (average Nei's D = 0.154), although higher than those reported for conspecific populations of fish, appear to be small when compared to the interspecific values among mugilid species (0.821 less than or equal to Nei's D less than or equal to 1.744). Phylogenetic trees obtained by genetic distance methods and discrete character parsimony analysis were of similar topology, except for the relationships within the genus Mugil and for the arrangement of M. cephalus populations
Equation of state of hexagonal closed packed iron under Earth's core conditions from quantum Monte Carlo calculations
No full textWe applied quantum Monte Carlo techniques to compute the equation of state of hexagonal closed packed iron in the range of pressure relevant to Earth's core. We used an accurate iron pseudopotential with a frozen Ne core. Trial wave functions have been obtained from density-functional theory (DFT) plane-wave calculations and expanded in systematically improvable B splines. Tests with various exchange-correlation functionals showed that the B3LYP functional is the one that provided the best trial wave functions. Diffusion Monte Carlo calculations were carried out using simulation cells with up to 96 atoms (1536 electrons), with some attempts to use up to 150 atoms, and corrected for finite-size errors using the scheme of Chiesa [Phys. Rev. Lett. 97, 076404 (2006)] and Kwee [Phys. Rev. Lett. 100, 126404 (2008)]. The calculated equation of state agrees closely with the experiments of Mao [J. Geophys. Res. 95, 21737 (1990)] and those of Dewaele [Phys. Rev. Lett. 97, 215504 (2006)]. It also agrees with the DFT data of Soderlind [Phys. Rev. B 53, 14063 (1996)] and Alfe [Phys. Rev. B 61, 132 (2000)], and therefore, reinforces those previous calculations
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