Search results for "activity index"
showing 3 items of 13 documents
Natural Radioactivity in Clay and Building Materials Used in Latvia
2015
Abstract This paper presents the results of natural radionuclide concentration and activity index study in materials used for construction in Latvia. Special attention is given to clay and clay ceramics. Concentrations of K-40 and Th- 232, U-238 radioactivity were determined using gamma-spectrometry method. In some building ware, maximal concentration of K-40 was 1440 Bq/kg, and of U-238 - 175 Bq/kg. In granite, the determined maximum concentration of Th-232 was 210 Bq/kg. It was found that radionuclide content in different period clay deposits can differ by more than two times, and up to five times in different clay ceramics. The results obtained are compared with analogous data from the o…
Emotional modulation of the attentional blink and the relation to interpersonal reactivity
2013
The extent of the attentional blink effect on detection rates in rapid serial visual presentations is modulated by the emotionality of the stimuli. Emotionally salient stimuli are detected more often, even if presented in the attentional blink period, and elicit an enlarged P3 response, which has been interpreted as enhanced consolidation. This effect correlates with individual differences in trait affectivity such as anxiety or dysphoria. Here, we ask if it is also related to the capacity to detect emotions in others, i.e., to interpersonal social traits. We therefore presented emotional and neutral images depicting social scenes as targets in an attentional blink design and measured detec…
Inconsistencies in the pozzolanic strength activity index (SAI) for silica fume according to EN and ASTM
2014
Published version of an article in the journal: Materials and Structures. Also available from the publisher at: http://dx.doi.org/10.1617/s11527-014-0457-6 Open Access New supplementary cementitious materials claimed to possess pozzolan properties emerge frequently. This development is driven both by economic and environmental pressures. Properties of new materials are compared with those of materials already well known, such as silica fume. Several test methods are standardized for making such comparisons, regulated by both European (EN) and American (ASTM) standards. Standardization indicates that procedures are secured to make comparisons valid and informative. In this article the sensit…