This topic, 2nd law of thermodynamics, includes:

• Thermal Efficiency: https://thermodynamics-engineer.com/thermal-efficiency/
• Carnot Cycle: https://thermodynamics-engineer.com/carnot-cycle/
• Clausius Inequality: https://thermodynamics-engineer.com/clausius-inequality/
• Entropy: https://thermodynamics-engineer.com/entropy/

More items will come soon 🙂