Abstract The species of the brachiopod Gigantoproductus are giants within the Palaeozoic sedentary benthos. This presents a dilemma as living brachiopods have low‐energy lifestyles. Although brachiopod metabolic rates were probably higher during the Palaeozoic than today, the massive size reached by species of Gigantoproductus is nevertheless unusual. By examining the diet of Gigantoproductus species from the Visean (Mississippian, Carboniferous) of Derbyshire ( UK ), we seek to understand the mechanisms that enabled those low‐metabolism brachiopod species to become giants. Were they suspension feeders, similar to all other brachiopods, or did endosymbiosis provide a lifestyle that allowed them to have higher metabolic rates and become giants? We suggest that the answer to this conundrum may be solved by the identification of the biogeochemical signatures of symbionts, through combined analyses of the carbon and nitrogen‐isotopic compositions of the occluded organic matrix within their calcite shells. The shells are formed of substructured columnar units that are remarkably long and a few hundreds of microns wide, deemed to be mostly pristine based on multiple analyses (petrography, cathodoluminescence ( CL ), scanning electron microscopy ( SEM ), electron backscatter diffraction ( EBSD ), transmission electron microscopy ( TEM )); they contain occluded organic fractions detected by TEM , nuclear magnetic resonance ( NMR ) and gas chromatography mass spectrometry ( GC ‐ MS ) analyses. We conclude that the gigantic size reached by the species of Gigantoproductus is probably the result of a mixotroph lifestyle, by which they could rely on the energy and nutrients derived both from photosymbiotic microbes and from filtered particulate food.
3-Benzoylpropionic acid undergoes continuous transition associated with pseudosymmetry melting upon heating. The transition stems from a directional steric crowding, which refutes the recent premise of its colossal thermal expansion.
Organic UV filters are used in many applications (personal-care products, components in packaging, dyes, etc). However, many issues remain related to their safety; their release into the environment is toxic for many organisms and their photodegradation products are possibly dangerous. Encapsulation of these molecules in a zeolitic matrix can avoid their dispersion and promote the enhancement of their properties. In this study, we report the structural characterization of the new LTL/OMC ZEOfilter, produced by encapsulating the organic Uv filter octinoxate (OMC, C 18 H 26 O 3 ) into synthetic zeolite L. In fact, for the further exploitation and the realization of tailor-made materials, it is fundamental to understand the interactions between the filter and the matrix. X ray diffraction, Rietveld structural analysis and Monte Carlo simulation result in a detailed description of the molecules’ setting and configuration. To fit the pores of the zeolite, it appears that the conformation of OMC molecules changes, in fact they present a bent tail, allowing suitable intermolecular distances. The results were also corroborated by FT-IR experiments. This interaction is the key point for the stability and efficacy of LTL/OMC ZEOfilter and may explain why, among different ZEOfilters, the cationic zeolites, and especially zeolite L, display the most promising features.
Treatments to reduce the leaching of contaminants (chloride, sulfate, heavy metals) into the environment from bottom ash (BA) are investigated, as a function of the ash’s particle size (s). The aim is to make BA suitable for reuse as secondary raw material, in accordance with the legal requirements. Such treatments must be economically feasible and, possibly, have to use by-products of the plant (in this case, steam in excess from the turbine). For the sake of completeness and comparison, carbonation is performed on those BA particle size classes that are not positively responsive to steam washing. BA is partitioned into four different particle size classes (s ≥ 4.75, 4.75 > s ≥ 2, 2 > s ≥ 1 and s < 1 mm, corresponding to 36, 24, 13 and 27 wt%, respectively). In the case of s ≥ 2 mm (60 wt%), steam washing is effective in reducing to under the legal limits the leaching of chlorides, sulfate and heavy metals (Zn, Cu, Cd, Pb). It has been observed that steam washing causes both removal and dissolution of thin dust adherent to the BA’s surface. BA with 2 > s ≥ 1 (~13 wt% of total BA) requires a combination of steam washing and carbonation to achieve a leaching below the legal limits. The finest BA fraction, s < 1 mm (~27 wt% of total BA), is treated by carbonation, which reduces heavy metals leaching by 85%, but it fails to sufficiently curb chlorides and sulfates.
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)