Brewster (1830a) points out that beautiful color effects will be seen if metallic salts are allowed to crystallize from solution under a microscope in polarized light. For this he recommends a glass-plate polarizer and a thin plate of agate or tourmaline as analyzer. The first one to equip a microscope with Nicol prisms was probably Talbot (1834a, 1837) who describes various observations with t...

Encapsulation is one of the main principles in object-oriented software construction. Reducing software component coupling and enforcing interface definition facilitates maintenance, reusability and incremental development, thus increasing software quality. Encapsulation is usually supported by specific access control (visibility) mechanisms as private or protected in Java and C++ or Eiffel’s e...

Complexes 11, 22 and 33 were synthetized according to adapted published protocols. Tris(3,3′,3′′-phosphinidynetris(benzenesulfonato)palladium(0) nonasodium salt nonahydrate] (complex 4), bathophenanthrolinedisulfonic acid disodium salt , bathocuproin disulfonic acid disodium, 2,2′-Biquinoline-4,4′-dicarboxylic acid dipotassium salt, triphenylphosphine-3,3′,3′′-trisulfonic acid trisodium salt li...

The transition from full glacial to interglacial conditions along the southern margin of the Laurentide ice sheet resulted in dramatic changes in landscapes and biotic habitats. Strata and landforms resulting from the Wisconsin Episode of glaciations in the area directly west of Lake Superior indicate a context for late Pleistocene biota (including human populations) connected to ice margins, p...

introduction agates are presumed as a kind of precious stone that could be formed in magmatic, metamorphic and even sedimentary environment. mechanism for agate formation is not clear and is produced in laboratories. some hot springs and geothermal activity or white chimneys in the ocean floor, have some deposits like chalcedony but never produce agate. agate formation temperature varies betwee...

New sustainable syntheses based on solid-state strategies have sparked enormous attention and provided novel routes for the synthesis of supported metallic alloy nanocatalysts (SMACs). Despite considerable recent progress in this field, most developed methods suffer from either complex operations or poorly controlled morphology, which seriously limits their practical applications. Here, we a st...

Abstract An extensive deposit of agate occurs in Pedro González Island the Gulf Panama. Previous archaeological research showed that was exploited between 6200 and 5600 cal BP to make stone tools found at oldest known Preceramic human settlement Pearl archipelago. We constrain here origin geological context through a geochemical study island. show it includes primary volcanic breccias, lavas, t...