alphabetical list of italian inventions a. aircraft with tractor configuration propeller: the world's first airplane having a 'tractor' configuration, propeller on the front, was the goupy no.2 first flight on 11 march 1909 designed by mario calderara and financed by ambroise goupy at the french firm blériot aéronautique. at the time, it was the fastest airplane in existence.
a natural genetic mutation produced gold actually yellowish orange rather than silver coloration. people began to breed the gold variety instead of the silver variety, keeping them in ponds or other bodies of water. goldfish were introduced into europe during the 17th century, and into north america in the 19th century. h
more formally, a metal–organic framework is a coordination network with organic ligands containing potential voids. a coordination network is a coordination compound extending, through repeating coordination entities, in one dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or a coordination .
friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. there are several types of friction: dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. dry friction is subdivided into static friction 'stiction' between non-moving surfaces, and kinetic friction between moving .
1935 – german authorities make the color-coding at vital aircraft parts obligatory; red for fire circuit-breakers, green for temperature regulators, yellow for throttles and brown for hydraulic circuits. 1930 – james irwin, american astronaut, was born d. 1991 .
jade refers to an ornamental mineral, mostly known for its green varieties. it can refer to either of two different minerals: nephrite, a silicate of calcium and magnesium, or jadeite, a silicate of sodium and aluminium. jade is featured prominently in asian art, but also has an important place in many other cultures.