1,720,985 research outputs found
Additively manufactured TiNiSn-based half-Heusler compounds enabled by in situ crack healing
No full textThermoelectric (TE) materials are traditionally manufactured by sintering of alloyed powders, followed by cutting the sintered specimen to the desired shape. This process is time-consuming, wasteful in terms of materials and energy, and costly, ultimately hindering the utilization of TE generators. Additive manufacturing (AM) offers a potential solution, but the inherently low thermal conductivity and brittleness of TE materials pose challenges for their fabrication via this approach. To address these issues, we developed a novel approach utilizing an in situ crack-healing mechanism. By blending Sn powder with partially pre-alloyed TiNiSn0.95Sb0.05 powder, parts were successfully fabricated via directed energy deposition method. Since Sn has a lower melting point relative to the half-Heusler phase, molten Sn served as an in situ healing agent during the AM process, efficiently backfilling cracks formed in previous layers. This phenomenon was confirmed by tracking the Sb content in the backfilled regions. Consequently, promising TE properties were achieved after heat treatment. This study introduces a new strategy to expand the range of not only TE materials but also other materials containing alloying elements or intermetallic compounds with low melting points, while offering a cost-effective approach for fabricating complex parts, providing a benefit for commercializing these products.
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
다중 주원소 합금설계방법으로 제조된 연자성체, 열전재료의 구조-특성 관계
No full text학위논문(박사) - 한국과학기술원 : 신소재공학과, 2021.2,[vii, 76 p. :]As a novel strategy of designing alloys, the concept of multiple-principal elements alloys has promoted an emerging development of alloys in undiscovered compositional areas. As a result, multiple-principal elements alloys have been reported to show various beneficial properties such as high fracture toughness, high-temperature strength, excellent strength-ductility balance as outstanding structural materials. However, until now most of the research has focused on understanding and optimizing their mechanical properties for structural applications. In this dissertation, we used this alloy design approach to soft magnetic and thermoelectric materials. Especially, we used advanced characterization such as atom probe tomography and transmission electron microscopy to understand the structure-property relationship. As a result, we revealed the effect of nanostructures and their compositions on their functional properties. We expect that the correlative characterization approach proposed in this dissertation could be competently used for revealing the structure-property relationships in wider field of materials science.한국과학기술원 :신소재공학과
백금·철 산소환원반응 촉매의 내구성 향상에 관한 연구
No full text학위논문(석사) - 한국과학기술원 : 신소재공학과, 2017.2,[vi, 54 p. :]Recently, (M=Fe,Ni,Co,Cu…) intermetallic compounds are being spotlighted as candidates for ORR catalysts. To form intermetallic compound, high temperature is required, but particles are aggregated in this process. In this study, we prevented particle aggregation by carbon coating. As a result, ECSA was almost maintained and structure was formed. exhibited in initial mass activity. After ADT 8,000 cycles, there wasn’t serious particle aggregation and composition was maintained. As a result, exhibited in mass activity, after ADT 8,000 cycles. We suggested intermetallic compounds are good candidates for the most active and durable ORR catalysts.한국과학기술원 :신소재공학과
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
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