(Appendix) Bulk inorganic chemistry at DSDP Leg 77 Holes

Clay mineralogic and inorganic geochemical investigations of Cretaceous and Cenozoic sediments of the western Gulf of Mexico lead to the following main conclusions. (1) Transition of lowermost Cretaceous continental to marine sedimentation is marked by a clay evaporitic stage, north of the Campeche Escarpment. (2) Existence of combined mineralogic and geochemical stratigraphy allows us to propose correlations between Sites 535 and 540, especially for the Albian. (3) Predominance of detrital clay assemblages is indicative of hot and variably humid continental climate until the early late Cenozoic. (4) Tectonic destabilization of the margins of Gulf of Mexico occurred at different periods, especially until the middle Cretaceous, with a mixed erosion of rocks and soils and temporary oxidized conditions of deposition. (5) Successive developments of confined perimarine basins occurred from the earliest Cretaceous until the Miocene, chiefly in the Florida area. The sources of inorganic materials were chiefly situated on the east of the studied area until the late Tertiary and after that in the Mississippi River basin. (6) Occasionally, volcanic activity influenced the clay mineralogy and mainly the geochemistry, and possibly contributed to the rather strong magnesian character of the deposition until the late Paleogene. (7) The argillaceous diagenesis is weak; variability of the carbonate diagenesis is marked by the relation Sr = f(CaO) and chiefly depends on the depth of burial, the clay content, the porosity, and the geologic age.

Seawater carbonate chemistry and growth, reproduction of calcifying and non-calcifying epibionts of a brown macroalga in a laboratory experiment

Seaweeds are key species of the Baltic Sea benthic ecosystems. They are the substratum of numerous fouling epibionts like bryozoans and tubeworms. Several of these epibionts bear calcified structures and could be impacted by the high pCO2 events of the late summer upwellings in the Baltic nearshores. Those events are expected to increase in strength and duration with global change and ocean acidification. If calcifying epibionts are impacted by transient acidification as driven by upwelling events, their increasing prevalence could cause a shift of the fouling communities toward fleshy species. The aim of the present study was to test the sensitivity of selected seaweed macrofoulers to transient elevation of pCO2 in their natural microenvironment, i.e. the boundary layer covering the thallus surface of brown seaweeds. Fragments of the macroalga Fucus serratus bearing an epibiotic community composed of the calcifiers Spirorbis spirorbis (Annelida) and Electra pilosa (Bryozoa) and the non-calcifier Alcyonidium hirsutum (Bryozoa) were maintained for 30 days under three pCO2 conditions: natural 460±59 µatm, present-day upwelling1193±166 µatm and future upwelling 3150±446 µatm. Only the highest pCO2 caused a significant reduction of growth rates and settlement of S. spirorbis individuals. Additionally, S. spirorbis settled juveniles exhibited enhanced calcification of 40% during daylight hours compared to dark hours, possibly reflecting a day-night alternation of an acidification-modulating effect by algal photosynthesis as opposed to an acidification-enhancing effect of algal respiration. E. pilosa colonies showed significantly increased growth rates at intermediate pCO2 (1193 µatm) but no response to higher pCO2. No effect of acidification on A. hirsutum colonies growth rates was observed. The results suggest a remarkable resistance of the algal macro-epibionts to levels of acidification occurring at present day upwellings in the Baltic. Only extreme future upwelling conditions impacted the tubeworm S. spirorbis, but not the bryozoans.

Thermal diffusion profile by NRA of Deuterium implanted in solid breeder blanket materials

This paper studies the relationship between aging, physical changes and the results of non-destructive testing of plywood. 176 pieces of plywood were tested to analyze their actual and estimated density using non-destructive methods (screw withdrawal force and ultrasound wave velocity) during a laboratory aging test. From the results of statistical analysis it can be concluded that there is a strong relationship between the non-destructive measurements carried out, and the decline in the physical properties of the panels due to aging. The authors propose several models to estimate board density. The best results are obtained with ultrasound. A reliable prediction of the degree of deterioration (aging) of board is presented. Breeder blanket materials have to produce tritium from lithium while fulfilling several strict conditions. In particular, when dealing with materials to be applied in fusion reactors, one of the key questions is the study of light ions retention, which can be produced by transmutation reactions and/or introduced by interaction with the plasma. In ceramic breeders the understanding of the hydrogen isotopes behaviour and specially the diffusion of tritium to the surface is crucial. Moreover the evolution of the microstructure during irradiation with energetic ions, neutrons and electrons is complex because of the interaction of a high number of processes.

New inorganic nanotube polymer nanocomposites: Improved thermal, mechanical and tribological properties in isotactic polypropylene incorporating INT-MoS2.

Environmentally friendly molybdenum disulfide (INT-MoS2) inorganic nanotubes were introduced into an isotactic polypropylene (iPP) polymer matrix to generate novel nanocomposite materials through an advantageous melt-processing route. The effects of INT-MoS2 content on the thermal, mechanical and tribological properties were investigated. The incorporation of INT-MoS2 generates notable performance enhancements through reinforcement effects, highly efficient nucleation activity and excellent lubricating ability in comparison with other nanoparticle fillers such as nanoclays, carbon nanotubes, silicon nitrides and halloysite nanotubes. It was shown that these INT-MoS2 nanocomposites can provide an effective balance between performance, cost effectiveness and processability, and should be of some interest in the area of multifunctional polymer nanocomposite materials.