1,720,974 research outputs found

    Laser damage testing of SiO2 and HfO2 thin films

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    part of "The EOS/SPIE Symposium on Optical Systems Design and Production

    Ground based Raman lidar for day and night measurements of water vapour in the boundary layer

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    The solar-blind Raman-lidar based on a KrF laser (248 nm) developed at Lecce’s University (407 208 N, 187 68 E) is described. The lidar is currently used for day and night measurements of water vapor. The dependence of the measurement range of the lidar on the laser beam divergence is investigated and it is shown that the KrF laser beam divergence can be reduced by a factor A10 by using a quite simple unstable cavity configuration. The maximum range which was limited to approximately 500 m for a A3 mrad divergence laser beam has increased up to 1200 m with a A0.3 mrad divergence laser beam since the field of view of the telescope was of 1 mrad. Water vapor profiles retrieved from lidar measurements under different operating conditions are presented. The effect of boundary-layer ozone absorption has also been investigated

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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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