abstract in order to study the effects of salinity and silicon application on biomass of leaves and root of purslane (portulaca oleracea l.), a greenhouse experiment was conducted at research greenhouse of ferdowsi university of mashhad using completely randomized desgin with three replications. employed two factors consisted of three levels of salinity using nacl (0.6, 11, 22 ds/m) and two lev...

of an internal rotation; the greater time for the carbon compound indicates some frictional resistance to rotation. Both dimethoxy compounds have similar relaxation times, as also have the tetramethoxy compounds. The greater size and substantially higher dipole moments of the silicon compounds, however, should produce a proportionately greater contribution from the molecular tumbling motion. Th...

During recent years, the silicon organic-inorganic compounds play the key role in medicinal chemistry and pharmaceutical industry. This is because of their similar chemical properties with carbon compounds. The second reason is related to their easy transfer from the cell membranes. So, molecular simulation and study the properties of novel organosilicon compounds can be more important. From th...

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...

abstract:any effects of wood coating with different compounds as nano-zinc, nano-chitosan, chitosan, silicon oil and flaxseed oil on surface properties as; wood color change, surface roughness and wettability were studied in the current research work. for this purpose, sample boards of beech wood were cut into sizes of 2×10×20cm. the specimens were coated with the noticed coatings and tested fo...

A TV series from the 1970s, ‘‘The Six Million Dollar Man,’’ imagines a former astronaut with bionic implants and superhuman strength acting as a secret agent for the government. Such enhancement of human abilities with artificial components (all at a reasonable price tag) might resonate with some of today’s scientists who are working on a more modest goal of augmenting the properties of cells a...

The view that silicon in animal tissues occurs in combination with organic groups has appeared repeatedly in the literature. As early as 1897 Drechsel & Winogradow described the extraction from goose feathers of an orthosilicate of the formula Si(OCuH5,90)4, stated to be an ester of a dihydric alcohol homologous with cholesterol. Isaacs (1924) inferred the presence of silicolipins in brain. Hol...