178,350 research outputs found
Geophysical characterization of hydrothermal systems and intrusive bodies, El Chichón volcano (Mexico)
No full text[1] The 1982 explosive eruptions of El Chichón volcano (Chiapas, Mexico) destroyed the inner dome and created a 1-km-wide and 180-m-deep crater within the somma crater. A shallow hydrothermal system was exposed to the surface of the new crater floor and is characterized by an acid crater lake, a geyser-like Cl-rich spring (soap pool), and numerous fumarole fields. Multiple geophysical surveys were performed to define the internal structure of the volcanic edifice and its hydrothermal system. We carried out a high-resolution ground-based geomagnetic survey in the 1982 crater and its surroundings and 38 very low frequency (VLF) transects around the crater lake. A 3-D inversion of the ground-based magnetic data set highlighted three high-susceptibility isosurfaces, interpreted as highly magnetized bodies beneath the 1982 crater floor. Inversion of a digitized regional aeromagnetic map highlighted four major deeply rooted cryptodomes, corresponding to major topographic highs and massive lava dome outcrops outside and on the somma rim. The intracrater magnetic bodies correspond closely to the active hydrothermal vents and their modeled maximum basal depth matches the elevation of the springs on the flanks of the volcano. Position, dip, and vertical extent of active and extinct hydrothermal vents identified by VLF-EM surveys match the magnetic data set. We interpret the shallow lake spring hydrothermal system to be mostly associated with buried remnants of the 550 BP dome, but the Cl-rich soap pool may be connected to a small intrusion emplaced at shallow depth during the 1982 eruption
Understanding the effect of nanomodifier addition upon the properties of fibre reinforced laminates
No full textThis work presents a survey of the effect of three different commercially available nano-modifiers on the mechanical properties of an epoxy/anhydride unidirectional carbon fibre reinforced laminates. The nano-modifiers consisted of an organo-modified layered silicate, vapour grown carbon fibre (VGCF) and a triblock copolymer (SBM). The work has shown that tensile modulus exhibited little difference between the unmodified laminates while a modest decrease was observed for the tensile strength. Properties related to the toughness of the matrix, demonstrated improvements compared to the unmodified laminate such as the notch sensitivity under compression, ILSS and G(IIC) performance. The improvement of the G(IIC) for the VGCF modifier in particular was found to be over 100%. It was suggested that high aspect ratio of the nano-additive helped to constrain the growth of the micro-cracks which in turn delayed failure. Mode I G(IC) performance however, was found to decrease as a result of the fibre tows preventing optimum dispersion of the modifier. The effect of this was a very high "effective" clay concentration in the interlayer resin rich regions and a less than optimum fibre dispersion, results in promotion of the propagating crack rather than inhibition
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
Rheological and Mechanical Properties of Compatibilized engineering plastic/Thermotropic polymer blends
No full textThe effect of compatibilization on the behavior of a polycarbonate/polymer liquid crystal blend
No full text"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
The Evaluation of the Match External Load in Soccer: Methods Comparison.
No full textThe aim of this study was to test the interchangeability of two match-analysis approaches for
external-load detection considering arbitrary selected speeds and metabolic power (MP) thresholds
in male top-class level soccer. Data analyses were performed considering match physical performance of team data (1200 player cases) of randomly selected Spanish, German and English first division championship matches (2013-14 season). Match analysis was performed with a validated semi-automated multi-camera system operating at 25 Hz. During a match players
covered 10673±348m of which 1778±208 and 2759±241m were performed at High-Intensity using
the speed (≥16 km·h-1, HI) and metabolic power notations (≥20 watt·kg-1, MPHI). High-intensity
notations were nearly perfect associated (r=0.93, p<0.0001). A huge method bias (980.63± 87.82m.
d=11.67) was found when considering MPHI and HI. Very large correlations were found between match total distance covered and MPHI (r=0.84, p<0.0001) and HI (r=0.74, p<0.0001). Players
high-intensity decelerations (≥-2 m·s2) coverage was very largely associated with MPHI (r=0.73,
p<0.0001). The results of this study showed that the speed and MP methods are highly
interchangeable at relative (magnitude rank) but not absolute (measure magnitude) level. As a
results the two physical match analysis methods can be independently used to track match external-
load in elite level players. However match-analyst decisions must be based on single method use in
order to avoid bias in external-load determination
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
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