Prehistoric

Tribological phenomena have been known to mankind since prehistorical times when friction between wooden sticks was used to produce fire. The first historical record of tribology described the use of lubrication in the... 

Latin carbo, charcoal) Carbon, an element of prehistoric discovery, is very widely distributed in nature. It is found in abundance in the sun, stars, comets, and atmospheres of most planets. Carbon in the form of microscopic diamonds is found in some meteorites. 

Sodium compounds are important to the paper, glass, soap, textile, petroleum, chemical, and metal industries. Soap is generally a sodium salt of certain fatty acids. The importance of common salt to animal nutrition has been recognized since prehistoric times. 

Anglo-Saxon, iron L. ferrum) Iron was used prehistorically ... 

Also of value is the study of the history of technology (24,25) that affords insights into the history of the development of civilization. The eadiest existing written records, treatises of crafts people and artists on the techniques and materials with which they worked, date back to medieval times (26—29). For prehistoric human activities, the record is in the objects which remain, and only through the study of these can knowledge in this regard be furthered. 

The first reported use of nickel [7440-02-0] Ni, was in a nickel—copper—2inc alloy produced in China in the Middle Ages and perhaps earlier. Alloys of nickel may have been used in prehistoric times. The metal was first isolated for analytical study in the mid-1700s by Axel Cronstedt, who named it nickel, which derives from the German word kupfemickel, or false copper. 

Carbon Blacks. Carbon black is one of the oldest pigments known. It was used by prehistoric peoples for painting pictures on cave walls, and commercially produced by the Chinese as early as 3000 BC. 

Early Industrial Enzymes. Enzymes were used in ancient Greece for the production of cheese (9). Early references to this are found in Greek epic poems dating from about 800 BC. Fermentation processes for brewing, baking, and the production of alcohol have been known since prehistoric times. 

Age Prehistoric and early days Ancient times Middle Ages Age of rationalism Modern Age ... 

Silica (Si02) and silicates have been intimately connected with the evolution of mankind from prehistoric times the names derive from the Latin silex, gen. silicis, flint, and serve as a reminder of the simple tools developed in paleolithic times (. i00000 years ago) and the shaped flint knives and arrowheads of the neolithic age which began some 20 000 years ago. The name of the element, silicon, was proposed by Thomas Thomson in... 

Vorgerbung,/. preliminary tanning, pretannage, vorgeschichtlich, a. prehistoric, vorgeschritten, p.a. see vorschreiten. votgesehen, p.a. see vorsehen. 

Energy theorists of cultural evolution are concerned with the whole sweep of cultural evolution, from prehistoric hunters and gatherers to modern industrial societies. This global, secular perspective is useful in assessing the relevance of ideas advanced to account for short periods of time in the histoi y of particular societies. Those who propose an energy theoi-y of cultural evolution emphasize the problem of causality-whether or not the amount of energy a... 

From the perspective of general energetics, the long span of human prehistoric development can be seen as the quest for a more efficient use of somatic energy, the muscular exertions used primarily to secure a basic food supply and then to gradually improve shelters, acquire more material possessions, and evolve a variety of cultural expressions. This quest was always limited by fundamental bioenergetic considerations Fifty to ninety watts is the limit of nsefnl work that healthy adults can snstain for prolonged periods of time (of course, short bursts of effort could reach hundreds of watts). 

Copper and copper alloys are amongst the earliest metals known to man, having been used from prehistoric times, and their present-day importance is greater than ever before. Their widespread use depends on a combination of good corrosion resistance in a variety of environments, excellent workability, high thermal and electrical conductivities, and attractive mechanical properties at low, normal and moderately elevated temperatures. 

During the 1950s, Professor W. F. Libby (1908-1980) of the University of Chicago and others worked out a method for determining the age of organic material It is based on the decay rate of carbon-14. The method can be applied to objects from a few hundred up to 50,000 years old. It has been used to determine the authenticity of canvases of Renaissance painters and to check the ages of relics left by prehistoric cave dwellers. 

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