The article is devoted to the actual problem of producing unburnt wall products compression molding with improved and high efficiency in terms thermal engineering properties. notes relevance, attractiveness, wide use pressed modern civil engineering. raw material composition production technology are described. traditionally used aggregates for reviewed their properties analyzed. High average d...

X-Ray powder diffraction studies have been used to measure the thermal expansion properties of three zeolites with the LTA topology and provide details of the underlying structural changes. Siliceous ITQ-29 and dehydrated and hydrated silver zeolite A have large negative, moderate negative and positive thermal expansion coefficients, respectively.

Round to oval, scalelike siliceous microstructures from cherts in Cambrian limestones of the western Yukon Territory suggest affinity with chrysophycean algae. At least six morphotypes present include porous forms with single branching processes and nonporous oval, ringlike forms. Partially dissolved specimens may indicate a contribution to contemporaneous or early diagenetic chert formation.

The reduction of Cu(II) oxide species in siliceous matrixes of different porosity (MFI, FAU, MCM-48) and in alumosilicate MFI was studied by temperature-programmed reduction in hydrogen (TPR), by X-ray absorption fine structure (after stationary hydrogen treatments), and by transmission electron microscopy. It was found that the reduction may proceed in one or in two reduction steps. The two-st...

A one-dimensional (1-D) ecological model, HABSIM, examined the initiation and maintenance of the 2001 red tide on the West Florida shelf (WFS). Phytoplankton competition among toxic dinoflagellates (Karenia brevis), nitrogen fixing cyanophytes (Trichodesmium erythraeum), large siliceous phytoplankton (diatoms), and small non-siliceous phytoplankton (microflagellates) explored the sequence of ev...

A comparative study of the microscopic morphology and chemical characteristics spicules Hexactinellids (Hexactinellida) with different structural features skeletons, as well freshwater Baikal sponge belonging to class common sponges (Demospongia), was carried out. The trace element composition determined by X-ray fluorescence spectrometry. siliceous contain many elements, arranged in decreasing...