postÂ·synÂ·apÂ·tic memÂ·brane. That part of the plasma membrane of a neuron or muscle fiber with which an axon terminal forms a synaptic junction. postsynaptic membrane. the excitable membrane of the DENDRITE next to the AXON at a synapse, that receives the nerve impulse.
Turbidity is the measure of relative clarity of a liquid. It is an optical characteristic of water and is an expression of the amount of light that is scattered by material in the water when a light is shined through the water sample. The higher the intensity of scattered light, the higher the turbidity. Material that causes water to be turbid include clay, silt, finely divided inorganic and organic matter, algae, soluble colored organic compounds, and plankton and other microscopic organisms. Turbidity makes water cloudy or opaque.
There are many factors that may cause cloudy or turbid water. Cloudy water can also be referred to as having high levels of turbidity. The most common causes of turbidity are organic matter, and/or colloidal solids that are too small and too fine to settle out properly. These suspended particles can cause problems with disinfection processes, and also be an indicator of bacterial activity in the water. Turbidity is measured in NTUâs, (nephelometric turbidity units). The turbidity of drinking water should always be less than 1 NTU. Most treated city water is less than .2 NTUs.