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New Fusion
Seems like there are new and important breakthroughs in fusion research:
Rusi Taleyarkhan is the principal investigator and a professor of nuclear engineering at Purdue. In effect, the research team is producing nuclear emissions in a simple desktop apparatus. The discovery allows, for the first time in history, the ability to use a simple mechanical force to initiate conditions comparable to the interiors of stars.
It's not cold fusion, but it sure sounds (har!) surreal. Here's to hoping it turns into something we can power our homes with some day!
PERMEABILITY OF MEMBRANES
Most natural (and some Man-made) membranes can be thought of as having extremely tiny pores or holes of various sizes; such partially permeable membranes allow some substances to pass but not others, depending on the relative particle sizes.
This effect is responsible for 2 phenomena which Biologists (including examiners) think are important: OSMOSIS and DIALYSIS.
THE PROCESS OF OSMOSIS
Osmosis is a special form of diffusion:
the MOVEMENT OF WATER
from a dilute solution to a more concentrated one
through a PARTIALLY PERMEABLE MEMBRANE.
This type of membrane (also called semi-permeable) allows only water, but not other (dissolved) substances to pass through.
All cells are surrounded by a cell membrane, which is partially permeable, and the cytoplasm contains dissolved substances (solutes), e.g. sugars, salts, proteins. Whether or not water enters or leaves the cell depends on the relative concentrations of the cytoplasm and the fluid surrounding them.
It is important to remember that a concentrated solution has a lower concentration of water than a dilute one, or water itself.