The structure refinement of a hastingsite (CI 0.91 p.f.u.) from West Ongul Island, Liitzow-Holm Bay, East Antarctica, has been carried out in order to characterise the effect of CIon the crystal structure. The composition of the CI-rich hastingsite is KO.69Nao.26Ca1.99Mg1.09Fe2+ 2.71Fe3+O.92MnO.\l4 Tio.lOAI2.31Sis.R30220Ho.99Clo.91Fo.10with unit cell parameters a 9.962(3), b 18.283(7), c 5.372(...

The rarity of Devonian tetrapods and the absence of tetrapods during the first 14 million years of the Mississippian (Romer’s Gap) have inspired hypotheses of fish-tetrapod evolutionary transition as an escape from difficult habitats such as deserts or stagnant waters. These hypotheses and Romer’s Gap are tested here using depth to calcic horizon in paleosols of the northern Appalachians as a p...

The activation of soil-fixed phosphorus is a long-term concern in soil science. In order to enhance the activation effect to soil-fixed phosphorus in red soil, different modified zeolite, through physical, chemical method and the associated both physics and chemistry, was used in this paper. The results showed as following: 1) the activated ability to soil-fixed phosphorus in red soil for modif...

Although various episodes of wet Quaternary climates have been suggested in studies of the Negev Desert, here we demonstrate that Reg soils, developed on flat alluvial surfaces and sensitive to minor changes in precipitation, indicate that the southern Negev has been permanently hyperarid at least since the middle Pleistocene. The wetter episodes were restricted to the northern Negev, currently...

In small-pore zeolite catalysts, where the size of the pores is limited by eight-ring windows, aromatic hydrocarbon pool molecules that are formed inside the zeolite during the Methanol-to-Olefins (MTO) process cannot exit the pores and are retained inside the catalyst. Hydrocarbon species whose size is comparable to the size of the zeolite cage can cause the zeolite lattice to expand during th...

background and objectives : zeolite is a group of anionic hydrated aluminosilicates with a tridimensional structure which has great implications in remediation of water, sediment and soil resources. the present research aims at physicochemical investigation, clay mineralogy and micromorphology of soils along rafsanjan-sarcheshmeh lithotoposequence, southeastern iran. materials and methods: the ...

In recent years, natural substances such as zeolite have been used to absorb heavy metals in soil in an attempt to decrease their availability to plants. Compared to other techniques, the use of zeolite is fast, clean, and inexpensive. This research was carried out to investigate the effects of an Iranian natural zeolite (clinoptilolite) on stabilizing Cd-contaminated soil treated with 0.01 M C...

The synthesis of calcium silicate supported zeolite membrane was carried out by second growth method. The chemical nature of the functionalizing agent on the formation of homogenous zeolite membrane was evaluated. One monomer and two cationic polymers were used: 3-aminopropyltriethoxysilane (APS), polyethylenimine (PEI) and polydiallyldimethylammonium chloride (PDDA). The support was subjected ...