06413_09 - I IAA (indoleacetic acid) See auxin. ice See...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
I IAA (indoleacetic acid) See auxin . ice See water . ice age A period in the earth’s history during which ice advanced towards the equator and a general lowering of tem- peratures occurred. The last major ice age, that of the Pleistocene period (some- times known as the Ice Age ), ended about 10 000 years ago. At least four major ice advances (glacials) occurred during the Pleistocene period; these were separated by interglacials during which the ice re- treated and temperatures rose. At present it is not known if the earth is between ice ages or is in an interglacial of the Pleis- tocene Ice Age. It has been established that ice ages also occurred during the Pre- cambrian (over 500 million years ago) and during the Permo-Carboniferous (about 250 million years ago). ice point The temperature at which there is equilibrium between ice and water at standard atmospheric pressure (i.e. the freezing or melting point under standard conditions). It was used as a Ü xed point (0 ° ) on the Celsius scale, but the kelvin and the International Practical Temperature Scale are based on the * triple point of water. iconoscope A form of television cam- era tube ( see camera ) in which the beam of light from the scene is focused on to a thin mica plate. One side of the plate is faced with a thin metallic electrode, the other side being coated with a mosaic of small globules of a photoemissive ma- terial. The light beam falling on the mo- saic causes photoemission of electrons, creating a pattern of positive charges in what is effectively an array of tiny capaci- tors. A high-velocity electron beam scans the mosaic, discharging each capacitor in turn through the metallic electrode. The resulting current is fed to ampli Ü cation circuits, the current from a particular sec- tion of the mosaic depending on the illu- mination it has received. In this way the optical information in the light beam is converted into an electrical signal. ICSH See luteinizing hormone . ideal crystal A single crystal with a perfectly regular lattice that contains no impurities, imperfections, or other de- fects. ideal gas (perfect gas) A hypothetical gas that obeys the * gas laws exactly. An ideal gas would consist of molecules that occupy negligible space and have negligi- ble forces between them. All collisions made between molecules and the walls of the container or between molecules and other gas molecules would be perfectly elastic, because the molecules would have no means of storing energy except as translational kinetic energy. ideal solution See raoult’s law . identical twins (monozygotic twins) Two individuals that develop from a sin- gle fertilized egg cell by its division into two genetically identical parts. Each part eventually gives rise to a separate individ- ual and these twins are therefore identi- cal in every respect. Compare fraternal twins .
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/29/2009 for the course CIVIL ENG 12345 taught by Professor Xhfxfh during the Spring '09 term at Amirkabir University of Technology.

Page1 / 28

06413_09 - I IAA (indoleacetic acid) See auxin. ice See...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online