1,721,097 research outputs found
Cosmological constraints on Ho\v{r}ava gravity revised in light of GW170817 and GRB170817A and the degeneracy with massive neutrinos
Full text linkProton Exchange Membrane Fuel Cell Model for a Small Power Plant with Experimental Validation
No full textDifferent Strategies to Alleviate Soil Compaction Risk During Tillage Operations
No full textCompaction causes soil degradation, but different strategies can help to mitigate this phenomenon, such as increasing soil strength under traffic and decreasing soil stress due to equipment features. Controlled traffic farming enhances soil compaction mitigation by confining all equipment transit to the traffic lane. Crop seedbeds remain undisturbed, improving crop performance and increasing yield. Controlled traffic needs equipment standardization for all operations, from tillage to harvest, which can overcomplicate equipment travel on public roads and use of contractors. This study investigates three strategies to alleviate soil compaction risk during tillage: Random traffic with tracks, with wheels and controlled traffic farming. Three scenarios were compared by using the following traffic indexes: Rut Length, Traffic Intensity, Mechanization Degree, and Field Load Index. Soil stresses in specific scenarios were calculated with the Terranimo® model. Collecting soil bulk density, penetrometer resistance, working time analysis, field traffic analysis and fuel consumption with telemetry was completed on a real scale thanks to a 19 ha field test on a farm in northeast Italy. The soil stress is higher in the Controlled traffic than in the other two random traffic scenarios due to the narrow width of the wheels used to decrease the trafficked area. The field index Ruth Length shows a higher value in CT caused by a lower working width. On Mechanization Degree the RT scenario has a 47% increase compared to CT and 21% more than RW due to the high power used. Lower bulk density and Cone Index were found in CT seedbed. CT shows a decrease in fuel consumption and CO2 emission due to higher traction efficiency
Synthesis of 1-acetoxy-2-alkyl-2,3-butadienes and/or 2,3-dialkyl-1,3-butadienes from 1,4-diacetoxy-2-butyne and alkyl heterocuprates
No full textAcOCH2C≡CCH2OAc (I) reacts with RCu.MgBrCl.LiBr [II, R = Pr, Me(CH2)4, (S)-EtMeCHCH2], prepd. by reaction of RMgCl with CuBr and LiBr, to form allenes CH2:C:CRCH2OAc (III) and butadienes H2C:CRCR:CH2, in yields depending on the I:II ratio. III react with other II to give unsym. butadienes. Mechanisms are proposed to account for the 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
Reversibility of Metal-Alkyl Intermediate Formation in the Rhodium-Catalyzed Deuterioformylation of 1-Hexene
No full text
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
- …
