We evaluated the use of ion-exclusion chromatographic systems for analyzing the behavior of inorganic ions (e.g., bicarbonate, sulfate, chloride, nitrate, phosphate, dissolved silicate, sodium, ammonium, potassium, magnesium, and calcium ions) in a suburban river located in Jakarta, Indonesia. Carbonate, phosphate, and silicate ion concentrations were determined using ion-exclusion chromatograp...

Single-crystals of the title compound, nona-potassium triyttrium dodeca-silicate difluoride, were obtained from flux synthesis experiments in the system SiO2-Y2O3-KF. The crystal structure belongs to the group of single-layer silicates and is based on silicate sheets parallel to (110). A single layer contains secondary (Q (2)) and tertiary (Q (3)) silicate tetra-hedra in the ratio 1:2 and is bu...

Alkaline solutions, such as sodium, potassium or lithium silicates, appear to be very promising as healing agents for the development of encapsulated self-healing concretes. However, the evolution of their mechanical and acoustic properties in time has not yet been completely clarified, especially regarding their behavior and related kinetics when they are used in the form of a thin layer in co...

potassium is an essential plant macronutrient. various microorganisms including bacteria and fungi, algae, yeast and mosses are able to decompose silicate minerals and to dissolve nutrient such as k, fe, zn and si. aamong them bacteria are more important. the aim of this study was to determine the ability of microbial populations for releasing soil potassium. this study was carried out as a fac...

Introduction. Laboratory data on the evaporation kinetics and isotope fractionation of evaporation residues of silicate liquids exposed to vacuum or lowpressure gas of solar or dust-enriched compositions provide constraints on processes that affected the evolution of primitive inclusions in meteorites. In earlier work we focused on evaporations of Type B CAI-like liquids [1,4]. Here we will ree...

The structure of weeksite, K1.26Ba0.25Ca0.12[(UO2)2(Si5O13)]H2O, orthorhombic, a 14.209(2), b 14.248(2), c 35.869(4) Å, V 7262(2) Å3, space group Cmmb, has been solved by direct methods using data collected with MoK X-radiation and a CCDbased detector and refined by full-matrix least-squares techniques, on the basis of F2 for all unique reflections, to an agreement factor (R1) of 7.0% and a goo...

Soils of the tropics and sub-tropics are typically acid and depleted of soluble sources of silicon (Si) due to weathering and leaching associated with high rainfall and temperatures. Together with intensive cropping, this leads to marginal or deficient plant Si levels in Si-accumulating crops such as rice and sugarcane. Although such deficiencies can be corrected with exogenous application of S...

In vitro dose responses of several calcium and potassium salts were determined on some commercially significant plant pathogens, including: Helminthosporium solani, Fusarium oxysporum f. sp. pisi race 2, Colletotricum coccodes, Phytophthora cactorum, Phytophthora cinnamomi, Phytophthora erythroseptica, Phytophthora infestans, Phytophthora megasperma, Pythium ultimum, and Venturia inaequalis. My...