C4 pathway A pathway of carbon fixation, found most commonly in tropical plants that have high rates of growth and photosynthesis and that are adapted to high temperatures, strong light, low carbon dioxide levels, and low water supply. Its importance lies mainly in its reduction of photorespiration.
PT 100 RTD means Resistance temperature detector(RTD) of platinum with 100 ohms resistance at zero degree centigrade.
Heating Degree Day - HDD. DEFINITION of 'Heating Degree Day - HDD'. The number of degrees that a day's average temperature is below 65oFahrenheit (18o Celsius), the temperature below which buildings need to be heated. The price of weather derivatives traded in the winter is based on an index made up of monthly HDD values.