124,626 research outputs found
Evaluation of polymerization stress correlated with the extent of polymerization of flowable composites.
No full textGoing 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
A study on the effect of micro and nano-debris impact on aerospace thermal barrier coating at high temperature
No full textA study on the cellular structure during stress solicitation induced by BioMEMS
No full textThe investigation of single cells is a topic in continuous evolution. The complexity of the cellular matrix, the huge variety of cells, the interaction of one cell with the other are all factors that must be taken into consideration in the study of the cellular structure and mechanics. In this project, we developed different types of bioMEMS for cell's stretching, both transparent devices based on silicon nitride and non-transparent silicon based. While the use of silicon devices is limited to reflection microscopes, transparent bioMEMS can be used with transmission and reflection microscopes but can also be easily coupled with other tools such as patch clamp analyzers or atomic force microscope. This improvement will open brand new possibilities in the biological investigation field. We used these two BioMEMS to stretch a single cell in a controlled way and, as a first investigation, we focused on its morphology. We noticed that during a controlled stretch, cells react to the applied deformation. A hysteretic behavior on the ratio between area and perimeter has been highlighted
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Contraction stress, elastic modulus, and degree of conversion of three flowable composites
No full textThe aim of this study was to measure the contraction stress of three flowable resin composites and to correlate the stress with the elastic modulus and the degree of conversion. One low-shrinkage (Venus Diamond Flow) and two conventional (Tetric EvoFlow and X-Flow) flowable composites were polymerized for 40 s with a light-emitting diode (LED) curing unit. Contraction force was continuously recorded for 300 s using a stress-analyser, and stress values were calculated at 40 s and at 300 s. The maximum stress rate was also calculated for each specimen. The elastic modulus of each composite was assayed using a biaxial flexural test, and degree of conversion was analysed with Raman spectroscopy. X-Flow exhibited higher stress values than the other tested materials. Venus Diamond Flow showed the lowest stress values at 40 s and at 300 s, and the lowest maximum stress rate. Stress values were correlated with elastic modulus but not with degree of conversion, which was comparable among all tested materials
Design, Prototyping and Testing of a Rotating Electrical Machine with Linear Geometry for Shipboard Applications
No full textConventional rotating electrical machines are characterized by stator and rotor structures featuring a cylindrical geometry around the shaft rotational axis. Although advantageous for mechanical reasons, the cylindrical geometry results in overall machine shapes and dimensions that may be unsuitable for installation. This particularly occurs in shipboard applications, where electric motors and generators are subject to stringent room constraints and need to be fit in unusually shaped compartments. This paper presents the development and test of a dual-shaft rotating permanent-magnet electric machine prototype having a linear structure that facilitates its onboard use for such applications as electric propulsion and rudder actuation. In fact, the proposed machine topology has overall dimensions which can be adjusted to fit the space available for installation. The operating concept and the detailed electromechanical design of the machine are first described. Then the manufacturing and factory test of the prototype under inverter supply are illustrated. Finally, the validation of the prototype as a boat propulsion variable-speed inverter-fed motor is presented. It is proved that, despite of its highly non-conventional electromechanical design, the machine can be effectively fed from a general-purpose inverter for permanent magnet motors
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
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