Introduction: Isheyevo, a metal-rich CH/CB-like meteorite, shows whole-rock δ 15 N enrichment up to ~+1500‰ [1]. Bonal et al. discovered rare chondritic clasts in Isheyevo containing mafic silicates, large bulk 15 N enrichments (δ 15 N from +1000 to 1300‰) and µm-sized " hotspots " with δ 15 N approaching +5000‰ [2,3]. The source of these high 15 N enrichments, whether due to molecular cloud, n...

While soluble silicate binders have been used effectively for decades in various end uses, recent developments and discoveries may improve and expand the use of silicates. This paper reviews the traditional use and chemistry of sodium silicate binders and also describes how surfactants, viscosity modifiers, lubricants and non-traditional setting agents can provide new characteristics and flexib...

We report here the synthesis and selected properties of various silicate ester derivatives (tetraalkoxysilanes) of the taxanes paclitaxel (PTX) and docetaxel (DTX) [i.e., PTX-OSi(OR)3 and DTX-OSi(OR)3]. Both the hydrophobicity and hydrolytic lability of these silicates can be (independently) controlled by choice of the alkyl group (R). The synthesis, structural characterization, hydrolytic reac...

The tendency of oxygen atoms to form just two bonds with a bond angle smaller than 180 allows the appearance of low energy atomic motions related to internal rotational degrees of freedom which, in a first approximation, involve neither bending nor stretching of bonds (“rigid unit modes” in silicates, “floppy modes” in glasses). A huge variety of compounds exhibit the oxygenbridge X-O-X basic u...

We investigate the thermal expansion of crystalline SiO2 in the β– cristobalite and the β-quartz structure with path integral Monte Carlo (PIMC) techniques. This simulation method allows to treat low-temperature quantum effects properly. At temperatures below the Debye temperature, thermal properties obtained with PIMC agree better with experimental results than those obtained with classical Mo...

The phases containing multiple chains in the series Ba",+1[Si2mOsm+d those with triple (m = 3), quadruple (m = 4) and quintuple (m = 5) tetrahedral chains were investigated by high resolution transmission electron microscopy. The resulting images could be correlated with the structures. Variations of the chain multiplicity (m) within single crystals were observed as well as faults in the packin...

Introduction: Impact-generated hydrothermal systems may have caused widespread alteration of the crust on early Mars. We previously explored the range of alteration products using several Martian meteorites as crustal proxies: LEW88516 [1-3], Dhofar 378, Chassigny [4], and Nakhla [5]. Overall, the dominating alteration phases are oxides, hydroxides, clay minerals, and other hydrous silicates. O...

In this paper we consider a new interconnection network motivated by molecular structure of a chemical compound SiO4. The different forms of silicates available in nature lead to the introduction of the silicate networks. We investigate various parameters related to this network. We provide an addressing scheme for the nodes of the network and also an algorithm that enables us to draw the silic...