1,720,973 research outputs found
Effect Of Processing Parameters On The Characteristics Of UNS 32760 Duplex Stainless Steels Powders
No full textDuplex stainless steels represent a promising alternative when aggressive/marine atmospheres characterize the component's final application. In this frame, grades with higher Pitting Resistance Equivalent Number (40 or above) may be used in hydrogen sulphide and chloride-containing environments. UNS 32760 Duplex Stainless Steel powders have been obtained through close-coupled gas atomization, starting from wrought bars. The paper analyses the effect of different parameters on the characteristics of the final powder in terms of granulometry, morphology, microstructure, and chemical composition (compared to the starting material), also taking into account light elements such as N, O, H, C, and S
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
Effect Of Process Gas Composition On The Characteristics Of Atomised UNS S32760 Duplex Stainless Steels Powders
No full textSuper duplex stainless steels (SDSS) combine the advantages of ferritic and austenitic steels and reach an excellent combination of mechanical and corrosion properties. In addition, high-level mass fractions of chromium, molybdenum, and intermediate nitrogen mass fractions have enabled the higher Pitting Resistance Equivalent Number of SDSS. One of the main goals of the research activity is to evaluate the possible nitrogen variation into the UNS S32760 (X2CrNiMoCuWN25-7-4, AISI F55, 1.4501) super duplex stainless steel powders produced by Vacuum induction melting Inert Gas Atomization (VIGA) (starting from metals scraps and wastes) with two different melt chamber gas atmospheres, Ar or N2. Another study objective concerns the influence of different atomisation gas, Ar or N2 (in combination with the two different melt chamber atmospheres), on powder properties. The identification of the optimal gas process parameters necessary to obtain AISI F55 powders with the correct chemistry composition, especially in terms of nitrogen content, is essential for any subsequent process techniques (L-PBF, 3D printing, MIM, ...) to get the best pitting resistance and a good balance in the α ferrite/austenite phase, crucial for the mechanical properties. Therefore, after sieving, the effect of the different gas process parameters on the characteristics of the final powder, in terms of granulometry, morphology, microstructure, chemical composition (also taking into account light elements such as N, O, H, C, and S) and rheology, was investigated
Different formation routes of pore structure in aluminum powder metallurgy alloy
Full text linkIn powder metallurgy (PM), severe plastic deformation (SPD) is a well-known technological solution to achieve interesting properties. However, the occurrence of pores in the final product may limit these properties. Also, for a given type of microstructure, the stereometric parameters of the pore structures, such as shape (represented by Aspect and Dcircle) and distribution (fshape, and fcircle), decisively affect the final properties. The influence of different processing routes (pressing, sintering and equal channel angular pressing (ECAP)) on pore structures in an aluminum PMalloy is discussed. The nature of porosity, porosity evolution and its behavior is explored. The correlation between pore size and morphology is also considered. The final pore structure parameters (Aspect, Dcircle, fshape, and fcircle) of studied aluminum alloys produced by different processing routes depends on the different formation routes
Influence of production batch related parameters on static and fatigue resistance of LPBF produced AlSi7Mg0.6
Full text linkIn laser powder bed fusion (LPBF), the influence material properties are often determined as a function of the inclination with respect to the build direction. In industrial production with variable component shapes and dimensions, the part orientation will often be a matter of the available space in the build volume. Additionally, build-to-build variability is an important factor that may impact the mechanical properties that are often not quantified. Such sources of variability are of great importance for highly demanding sectors such as aviation and aerospace, where lightweight Al-alloys are often used with the geometrical freedom given by the LPBF process. Hence, this work systematically investigates the influence of production batch-related parameters together with part inclination in the LPBF of AlSi7Mg0.6 alloy. Three builds were executed to quantify the impact of the batch, part position, and inclination on the static and fatigue resistance of the alloy in a completely randomized experimental design using an industrial LPBF machine. The results were analysed by the appropriate statistical methods both for discrete and functional data. The results showed that while the part orientation only influenced the static properties, the part position significantly affected the fatigue life demonstrated by the different low cycle fatigue life coefficients
A new soft magnetic composites material for electrical machine: Improvement of mechanical properties with high molding pressure
No full textSeveral developments concerning the electrical machines have been recently focused: new technologies and materials can improve the efficiency of the machines and of their production processes. With the availability of new magnetic materials, it is now possible to replace ferromagnetic laminated steels with Soft Magnetic Composites (SMC), opening to the possibility to obtain parts having shapes otherwise impossible and with better performances in medium and high frequencies. Some commercial products are available in the market, but with limited mechanical properties for the introduction in electrical machines. The will to improve the mechanical properties still retaining similar magnetic characteristics led the research activity to special iron powders and selected Epoxy and Phenolic resins as binders. The process has been improved investigating different molding pressures and different binder percentages. The results encourage to carry on the research exploring further improvements
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
- …
