1,200,081 research outputs found
4577 P. A. La Due to J. D. B. Stillman, 1849
No full textThis is Letter of introduction from P. A. La Due to his brother J. D. B. La Due. P.A. introduces his friend Bernard J. Reid to his brother. La Due's brother lives in California, where Reid is traveling
Seabed foraging by Antarctic krill: Implications for stock assessment, bentho-pelagic coupling, and the vertical transfer of iron
No full textA compilation of more than 30 studies shows that adult Antarctic krill (Euphausia superba) may frequent benthic habitats year-round, in shelf as well as oceanic waters and throughout their circumpolar range. Net and acoustic data from the Scotia Sea show that in summer 2-20% of the population reside at depths between 200 and 2000 m, and that large aggregations can form above the seabed. Local differences in the vertical distribution of krill indicate that reduced feeding success in surface waters, either due to predator encounter or food shortage, might initiate such deep migrations and results in benthic feeding. Fatty acid and microscopic analyses of stomach content confirm two different foraging habitats for Antarctic krill: the upper ocean, where fresh phytoplankton is the main food source, and deeper water or the seabed, where detritus and copepods are consumed. Krill caught in upper waters retain signals of benthic feeding, suggesting frequent and dynamic exchange between surface and seabed. Krill contained up to 260 nmol iron per stomach when returning from seabed feeding. About 5% of this iron is labile, i.e., potentially available to phytoplankton. Due to their large biomass, frequent benthic feeding, and acidic digestion of particulate iron, krill might facilitate an input of new iron to Southern Ocean surface waters. Deep migrations and foraging at the seabed are significant parts of krill ecology, and the vertical fluxes involved in this behavior are important for the coupling of benthic and pelagic food webs and their elemental repositories
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going 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
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Two Dimensional Numerical Model to Predict the Thermal-Chemical Degradation of a piece of Carbon Fibre Composite (CFC) due to Laser Ablation
No full textThere is a growing interest in using carbon fibre composites (CFC) as a high tech construction material. The reason for this is that CFCs have similar mechanical performance to that of the more traditionally used materials like aluminium alloys, whilst being considerable lighter. The benefits of using a lighter material are vast. However whilst CFC have similar structural properties to that of aluminium its electrical and thermal properties are very different. This becomes important if CFCs are placed in an environment where the pieces of CFC could be struck by lightning as this interaction will damage the panels [1]. Previous studies published by N. Jennings and C. J. Hardwick [2] and F Lago et. al. [3] have attempted to model the damage caused to a piece of CFC due to a lightning strike. However these models have only considered very simple degradation methods and also did not include gas transport. The study presented here is an expansion of what has been discussed previously [4]. A two dimensional numerical model has been built which is designed to predict the damaged caused to a piece of CFC due to a lightning strike. Initial verification of the model is conducted by decoupling the thermal physics from the electrical effects and damaging the pieces of CFC by using laser ablation. The two dimensional numerical model (2D) includes thermal chemical degradation of the polymer via pyrolysis, the resultant gas transport through the decomposing material and carbon fibre vaporisation. An image of the x-ray tomography results of the laser ablated CFC samples are shown in figure 1. The predictions from the 2D model provide a reasonable agreement with the experimental results. Although further expansion of the model, into three dimensions, is required before a true validation of the numerical predictions can be achieved
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
Dr. Edward P. Wimberly, ITC, July 2011
No full textThis video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
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