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Abstract Aerosols significantly influence atmospheric processes such as cloud nucleation, heterogeneous chemistry, and heavy‐metal transport in the troposphere. The chemical and physical complexity of atmospheric aerosols results in large uncertainties in their climate and health effects. In this article, we review recent advances in scientific understanding of aerosol processes achieved by the application of quantum chemical calculations. In particular, we emphasize recent work in two areas: new particle formation and heterogeneous processes. Details in quantum chemical methods are provided, elaborating on computational models for prenucleation, secondary organic aerosol formation, and aerosol interface phenomena. Modeling of relative humidity effects, aerosol surfaces, and chemical kinetics of reaction pathways is discussed. Because of their relevance, quantum chemical calculations and field and laboratory experiments are compared. In addition to describing the atmospheric relevance of the computational models, this article also presents future challenges in quantum chemical calculations applied to aerosols. 

Lime kiln dust (LKD) is a fine particulate material by-product produced during the lime burning processes. Current reuse options are chiefly focused on reuse in the cement industry which are limited by the inherent porosity of this by-product. Due to the presence of calcium (Ca), magnesium (Mg) and other elements which can serve as micronutrients to the plants, LKD has the potential to be used as a replacement for conventional liming materials for both soil pHKCl increase and plant supplement with secondary major- (Ca and Mg) and micronutrients (Mn, Cu, Zn and Ni). The work described here outlines the investigation of physicochemical properties of pelletized LKD materials and their effect on soil pHKCl, available Ca and Mg content in the soil as well as straw and grain yields of spring barley. LKD were analyzed using X-ray diffraction, scanning electron microscopy with energy dispersive analysis, while detailed chemical analysis of both pelletized LKD and soil was performed using Atomic Absorption Spectroscopy. Pellet size and major element composition were used as chief indicators for the liming capacity of LKD. It was shown that low acidic soil (pHKCl 5.4) can be conditioned using fine (0.1–2 mm) pelletized LKD due to the high release rates while coarse pellets (5–8 mm) did not significantly increase available Ca and Mg content in soil and did not reach optimum pHKCl range even after 48 weeks. The highest application rate of LKD at 4 t/ha increased spring barley grain yield compared to control but the increase was not statistically significant. Thus, pelletized lime kiln dust could be a potential alternative to natural limestone or dolomite minerals as liming material for acid soils with the pellet size determining the liming kinetics. 

Abstract The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150–200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.