Laws of Thermodynamics and Related Concepts

Flashcards for Laws of Thermodynamics, Heat transfer, Water Vapor and Humidity, and Surface tension/Laplace's law

Conduction

The transfer of energy by direct contact between hot & cold molecules; mainly occurs in solids.

Convection

Involves mixing of fluid molecules at different temperatures; air is warmed in one location and circulated.

Radiation

Heat transfer without direct physical contact, even in a vacuum.

Melting

Changeover from the solid to a liquid state.

Melting Point

Temperature at which a solid changes to a liquid.

Latent Heat of Fusion

Extra heat energy required to change 1 gram of solid to a liquid.

Freezing

Heat energy is transferred from a liquid to a solid.

Sublimation

Transition from a solid to a vapor without becoming a liquid.

Liquid Pressure

The pressure exerted by a liquid depends on its height (depth) and weight density.

Pascal’s Principle

The pressure of a given liquid is the same at any specific depth, regardless of the container's shape, and acts equally in all directions.

Buoyant Force (Buoyancy)

Liquids exert an upward supporting force on submerged objects.

Aerosols

Suspensions of solid articles in gases.

Boiling Point

Temperature at which liquid's vapor pressure exceeds atmospheric pressure.

Latent Heat of Vaporization

Heat energy required to vaporize a liquid.

Evaporation

Change of a liquid into a gas at temperatures lower than its boiling point.

Water Vapor

Invisible gaseous form of water that exerts pressure.

Humidity

The amount of water vapor or moisture in the atmosphere.

Absolute Humidity (AH)

Actual water vapor content in a gas.

Relative Humidity (RH)

Ratio of actual water vapor content to saturated capacity at a given temperature, expressed as a percentage.

Condensation

A gas turns back into a liquid.

Dew Point

Temperature at which condensation begins.

Humidifier

Maintains molecular water in a gas.

Percent Body Humidity (%BH)

Ratio of actual water vapor content to water vapor capacity in saturated gas at body temperature (37°C).

Humidity Deficit

Amount of water vapor the body must add to inspired gas to achieve saturation at body temperature (37° C).

Surface Tension

Results from an imbalance of intermolecular forces existing at a gas-liquid surface.

Laplace's Law

Spherical structures that demonstrate the interaction between distending pressure and surface tension forces as a sphere’s radius varies inversely

Pulmonary Surfactant

Reduces surface tension, produced by alveolar type II epithelial cells.