1,721,127 research outputs found
SPECIAL ISSUE: Workshop on Modeling Geophysical Systems by Statistical Mechanics Methods; 27 April-2 May 2008 FOREWORD
No full textA method for emanation coefficient measurements of 222Rn and 220Rn from soils
No full textA new method to determine emanation coefficient of 222Rn and 220Rn from soil samples is presented. The aim of the present work is to obtain a useful, rapid and noise free method to make soil sample measurements. The method is based on the measurements of specific activities of 220Rn and 222Rn in a sealed chamber using α-spectrometry and on the measurements of specific activities of 232Th and 226Ra using γ-spectrometry. The specific activities of radon isotopes are measured using the electrostatic collection of polonium isotopes on the silicon surface barrier detector mounted at the top of a chamber containing the soil sample. In the chamber volume, the process of balance has been studied and the results show that the time needed to achieve the equilibrium is shorter than in the presence of free exhalation. © 1997 Published by Elsevier Science Ltd
Self-sustained oscillator as a model for explosion quakes at Stromboli Volcano
Full text linkWe analyze seismic signals produced by
explosion-quakes at Stromboli Volcano. We use standard
nonlinear procedures to search a low-order effective dynam-
ics. The dimension of the reconstructed phase space depends
on the number of samples. Namely larger time lengths cor-
respond to dynamical systems of different complexity. If we
restrict the analysis to the signal associated directly to the
source (Chouet et al., 1997), we obtain a phase space dimen-
sion equal to two. We reproduce this part of the signal with a
simple single self-sustained oscillator
Radon emanation and exhalation rates from soils measured with an electrostatic collector
No full text
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
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