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TEXT B: MEDIA ,

solid - fluid - (

) liquid - to subject - shearing stress -

mode - ,

1. , "to affect": The transfer processes are affected by the medium... - ...

2. "solid" "fluid"; "fluid" "liquid". , , , . SOLID - a firm substance; not liquid or a gas. FLUID - able to flow easily, like water or a gas, not solid, as fluid substances. LIQUID - a substance that is neither a solid nor a gas, e.g. Air is a fluid but not a liquid. Water is both a fluid and liquid.

TEXT

1. All matter is made up of solid, liquid, or gas or a combination of them. Since the transfer processes are affected by the medium in which the changes occur, it is imperative to understand the characteristics of each state.

2. A solid is generally thought of as a substance which offers resistance to change of shape (deformation), whereas, a fluid will deform continuously when subjected to a shearing stress, no matter how small. The mode of resistance distinguishes between a solid and a fluid.

3. A fluid may be either liquid or gas or a combination of the two. Fluids conform to the shape of their container. A liquid has a free surface, but a gas fills the entire container and has no free surface.

to conform - to compress - shape - substance - compressible - medium - (.. media) incompressible -

4. We readily think of water and air as fluids, but many other substances which behave quite differently are also fluids, e.g. asphalt, glass. Blood is a fluid whose behavior varies widely, depending upon its content of hemocytes (blood cells), sugar, and plasma.

5. Fluids whose density changes are insignificant in a given process are said to be incompressible. Under normal conditions liquids are considered incompressible: gases and vapors may be compressible since their density may change considerably.

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