User:Milton Beychok/Gallery Subpages

Some paraphrased material taken from my Sixth Edition of Perry's Handbook for Chemical Engineers, published in 1984:

From "Thermodynamics" on page 4-52

The words system, surroundings and boundary are first defined as:

A system is any object, any quantity of matter, any region, etc. selected for study and mentally set apart from everything else which is then called the surroundings. The imaginary envelope enclosing the system and separating it from its surroundings is called the boundary of the system.

Then heat is defined as:

Heat is energy crossing that crosses a system boundary under the influence of a temperature difference or gradient between the system and its surroundings. A quantity of heat, Q, represents an amount of energy in transit between a system and its surroundings and is not a property of the system.

From "Modes of Heat Transfer" on page 10-8 (in "Heat Transmission" chapter)

There are three fundamentals types of heat transfer: conduction, convection and radiation. All three types may occur at the same time, and it is advisable to consider the heat transfer by each type in any particular case.

Heat Transfer (1992) by Anthony F. Mills

From "Modes of Heat Transfer"

Go here and then use search box to find "heat defined" which will take you to a number of snippets. The top one is "Modes of Heat Transfer", Section 1.3 on page 7. Click on that snippet and it becomes a full page. This is a much more complete discussion of the three modes of heat transfer.