Farm system boundaries: Discussion of system boundaries in Chapter 3 mainly relates to farms of this type. Briefly, boundaries of Type 2 farm systems (and of Types 1, 3 and 4) segregate them distinctly from the external world, but the boundaries between individual farms are relatively weak.
What is Chromium? Chromium is a steel-gray lustrous metal that is important as an additive in the manufacture of steel alloys (chrome steel, chrome-nickel steel, stainless steel) and greatly increases the durability and resistance of these metals; hence its use in metal prosthetic implants.
Named from the Greek word meaning âcolorâ, chromium is a lustrous, hard, bluish-gray metal. It can be polished to a mirror-like finish and is often used as a decorative and protective plating or finish. Like vanadium, chromium hardens steel, so it is frequently used in alloys, especially stainless steel. Chromium compounds are all strongly colored, and this characteristic gives chromium its name. Chromium compounds are used as a yellow coloring agent in the textiles industry. It also is used in the tanning of leather. Rubies and emeralds gain their color from chromium impurities.