Biophysics Lecture 2 (HUE AHST) 2024-2025 PDF

BIOPHYSICS FIRST LEVEL 2024-2025 Prepared By Dr. Nermin Ali Dr. Enas Lotfy Lec No. 2 Course Code: FAC-104 Page 1 Heat and Thermodynamics Page 2  Thermodynamics, science of the rel...

BIOPHYSICS FIRST LEVEL 2024-2025 Prepared By Dr. Nermin Ali Dr. Enas Lotfy Lec No. 2 Course Code: FAC-104 Page 1 Heat and Thermodynamics Page 2  Thermodynamics, science of the relationship between heat, work, temperature, and energy. Thermodynamics deals with the transfer of energy from one place to another and from one form to another. Heat is a form of energy corresponding to a definite amount of mechanical work. Page 3  Definitions Temperature: is an interpretation to the amount of the internal energy of the system. Heat: is defined as the transfer of energy across the boundary of a system due to a temperature difference between the system and its surroundings. Thermal equilibrium: is a situation in which two objects would not exchange energy by heat or electromagnetic radiation if they were placed in thermal contact. Page 4  Zeroth law of thermodynamics (the law of equilibrium): If objects A and B are separately in thermal equilibrium with a third object C, then A and B are in thermal equilibrium with each other. Thermometers: are devices to measure temperature, and all of its types depends on the same principle that some physical property (volume, color, dimension, resistance, etc.) changes with the temperature. Page 5  Temperature scales There is different scales by which temperature can be measured including Celsius, Kelvin and Fahrenheit scales. Every scale was designed based on two fixed points (lower fixed point at which pure water freezes and upper fixed point at which pure water boils and evaporates). Page 6  Temperature scale conversion Celsius Scale Kelvin Scale Fahrenheit Scale Steam point Steam point Steam point Higher calibration point (100 oC ) (373 oK) (212 oF) Ice point Ice point Ice point Lower calibration point (0 oC) (273 oK) (32 oF) Conversion TC = TK - 273.15 TK = TC +273 TF =(9/5) TC + 32 Page 7 Thermometers and temperature scale Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Simple Thermocouples are consisting of two wires of different metals joined to each other and to a voltmeter. The reading on the voltmeter increases as the temperature of the junction increases, due to the increased EMF at the junction. Page 16 Advantages: (1)It has a very large scale (-200 to 1500oC) (2)It cheap and easy to use. (3)It can be used to measure rapidly fluctuating temperatures. Page 19 Or Page 20  Thank You Course Code: FAC-104 Page 21