1,721,110 research outputs found
Reclassification of Spheroidal Graphite Ductile Cast Irons Grades According to Design Needs
Full text linkThe classification of grades inside a material family should be based on the properties required by design procedures. This paper proposes a reclassification of spheroidal graphite ferritic pearlitic and ausferritic (ADI) ductile cast irons grades based on yield strength (YS), strength ratio (SR) UTS/YS and elongation at fracture (EF). In fact, these parameters are fundamental for the static assessment according to the procedures FKM Guideline and BS 7910:2005. Static assessment at room temperature, involving plastic deformation and depending on the wall thickness and stress state triaxiality, is here proposed as the most significant for the material classification. All other properties (e.g., fatigue under cyclic loads, high strain rates and temperature effect, etc.) should be reported with reference to the classification mentioned above. SR and EF control the plastic deformation at the notch tip, where maximum calculated elastic stress is redistributed. Minimum YS is usually assumed as the basic parameter for static and cyclic loading design. Because of the inverse relationship that exists between strength and ductility, Brinell hardness control and material quality index should be adopted as Material Quality Control tools, preventing from a too low EF. Fracture Toughness and its ratio with YS must be considered for preventing brittle fracture due to the presence of flaws. Fracture toughness definitions and available data are not sufficiently consistent for a correct comparison between different material grades. A surrogate Charpy energy measurement is indicated for an indirect estimate of toughness
On microstructure development and inclusion generation in continously cast resulphurized steel
No full textEffect of size and distribution of the reinforcement on the composite fracture mechanics behaviour
No full textDefinizione dei parametri critici nel processo di ricottura statica in campana ad idrogeno
No full textSperimentazione e modellistica del processo di ricottura in campana ad idrogeno
No full textLa ricottura statica in campane alimentate ad idrogeno è uno dei trattamenti di ricottura maggiormente utilizzati durante il ciclo di lavorazione a freddo di acciai destinati alla formatura per impieghi automobilistici. L'impiego di idrogeno all'interno dei forni viene realizzato per migliorare la rapidità ed uniformità del trattamento di ricottura. D'altra parte, nonostante questo metodo di ricottura sia impiegato da diversi anni, ancora oggi la regolazione viene realizzata su basi empiriche e senza conoscere alcuni aspetti fondamentali, quali la conducibilità termica e l'influenza delle velocità di riscaldamento sul processo di ricottura. Per questa ragione sono state implementate delle misure termiche durante il processo di ricottura mediante piazzamento delle termocoppie in diverse punti delle bobine di nastro trattato e a questa analisi è stato affiancato un processo di simulazione al calcoltore che ha consentito di stabilire i valori di conducibilità termica propri dei moti gassosi convettivi che si instaurano all'interno del forno. E' stato valutato l'effetto di diverse procedure di ricottura sulla struttura metallografica degli acciai ricotti, ma va segnalato che i risultati ottenuti circa quest'ultimo aspetto necessiteranno di ulteriori approfondimenti
Microstruttura, trattamenti termici e proprietà meccaniche degli acciai inossidabili bifasici, GIORNATA DI STUDIO AIM - Marzo 2003
No full text
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
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