residence time: Tr = V/I [T], a measure of the average time a molecule of water spends in a reservoir. The residence time defined for steady-state systems is equal to the reservoir volume divided by the inflow or outflow rate.

Residence time – is the average amount of time a substance spends in a particular compartment or reservoir. It is defined numerically as the steady-state amount of material in a reservoir divided by its total rate of inflow (or outflow).

Residence time is a measure of the reactivity of a substance in a reservoir.

Residence time is defined as the amount of water in a reservoir divided by either the rate of addition of water to the reservoir or the rate of loss from it.

Example in Chemical Oceanography: How do we calculate residence time? 1) Determine how much sodium is in the ocean. 2) Determine the annual Na+ flux via rivers. Residence time (in years) = Amount of sodium in the ocean of sodium in the ocean Amount of sodium being added (or removed) to the ocean each year.

The residence time in lakes and glaciers varies between 20 and 100 years, but the longest residence times are in the ocean (3,200 years) and in the groundwater (up to 10,000 years). The importance of the water cycle for our climate is significant.

In size-exclusion chromatography, the residence time of a molecule is related to its volume, which is roughly proportional to its molecular weight. Residence times also affect the performance of continuous fermentors.

Table 2.1 Residence times for water in the water cycle.

: the duration of persistence of a mass or substance in a medium or place (such as the atmosphere)

Space Time – For no dispersion/diffusion and v = v0, the space time equals the mean residence time. Internal Age Distribution, = Fraction of molecules inside the reactor that have been inside the reactor between a time and .

So, why is MRT important? It can be used to estimate the average time a drug molecule spends in the body. It can also be used to help interpret the duration of effect for direct-acting molecules (e.g. blood pressure lowering agents).

Residence time of flaming combustion was defined as the period where temperatures exceeded 3008C. This temperature threshold has been found in laboratory and field-based studies (Burrows 2001; Taylor et al.

The maximum flame temperature observed was ~1100°C near the flame base and, when observation height was normalised by flame height, flame temperature exponentially decreased to the visible flame tip where temperatures were ~300°C.

Fire is so hot that it can melt metal, vaporise vegetation instantly and scorch the earth, consuming all organic matter in the soil. Inside the fire zone temperatures can reach 1600 degrees and the temperature at the base of the flames can be in the order of 1100 degrees with the tips around 600.

At what temperatures do forest fires burn? An average surface fire on the forest floor might have flames reaching 1 meter in height and can reach temperatures of 800°C (1,472° F) or more. Under extreme conditions a fire can give off 10,000 kilowatts or more per meter of fire front.

Largest fires of the 21st-century

Don’t try to outrun a fire over a long distance; many firefighters have died this way when the fire caught up to them. And never run uphill to a safe spot, unless it’s less than 20 feet away, because fires move much faster uphill than across flat or downhill terrain, and people move slower.

3,400ºC

Blue flames have more oxygen and get hotter because gases burn hotter than organic materials, such as wood. For example, the element lithium will produce a pink flame, while the element tungsten will produce a green flame.

reddish