Showing papers in "Scientific American in 1978"
734 citations
TL;DR: Changes in the amount of blood flowing in areas of the human cerebral cortex reflect changes in the activity of those areas, as revealed by scintiscanning techniques following the injection of xenon-133.
Abstract: Changes in the amount of blood flowing in areas of the human cerebral cortex reflect changes in the activity of those areas. These changes are graphically revealed by scintiscanning techniques following the injection of xenon-133. (ERB)
592 citations
309 citations
TL;DR: In this article, three passive systems are used to cool a building in Iran: a wind tower, a domed roof and an air vent, which can even keep water cold and ice frozen from the winter until the height of the long, hot summer of the country's arid central and eastern plains.
Abstract: The internal environment of a modern building can be a comfortable one no matter how uncomfortable external environment is. In Iran certain traditional building designs achieve more than a flattening of the temperature curve; they circulate cool air through the building and can even keep water cold and ice frozen from the winter until the height of the long, hot summer of the country’s arid central and eastern plains. Three passive systems cool this building in the Iranian city of Yazd: a wind tower, a domed roof and an air vent. Although the summer days in arid regions are extremely hot, the summer nights are cool. Several features of traditional Iranian architecture are designed to take advantage of this wide daily temperature range. The wind tower operates by changing the temperature and thus the density of the air in and around the tower. Conditioning of air by a wind-tower system with an underground stream is shown in this psychrometric chart.
283 citations
266 citations
209 citations
TL;DR: In this article, the significance of tokens with respect to communication, social structures, and cognitive skills is discussed. But they do not discuss how they revolutionized the use of symbols, and how they presaged writing.
Abstract: I t is the nature of archaeological research to deal with data and their interpretation. . I use the facts as well as the hypotheses I have presented on the token system to reflect more broadly on the significance of tokens with respect to communication, social structures, and cognitive skills. [This reading] deals with the place of tokens among other prehistoric symbolic systems. After presenting relevant aspects of symbolism from the Paleolithic to the Neolithic period, I will analyze what the tokens owed to their antecedents, how they revolutionized the use of symbols, and how they presaged writing.
170 citations
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TL;DR: On a springy new indoor track at Harvard University runners can run faster than they can on standard tracks.
Abstract: On a springy new indoor track at Harvard University runners can run faster than they can on standard tracks. The design of the track was arrived at through a close analysis of the mechanics of human running.