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  2. Chemical oxygen demand - Wikipedia

    en.wikipedia.org/wiki/Chemical_oxygen_demand

    The COD can also be estimated from the concentration of oxidizable compound in the sample, based on its stoichiometric reaction with oxygen to yield CO 2 (assume all C goes to CO 2), H 2 O (assume all H goes to H 2 O), and NH 3 (assume all N goes to NH 3), using the following formula: COD = (C/FW)·(RMO)·32. Where

  3. Maximum sustainable yield - Wikipedia

    en.wikipedia.org/wiki/Maximum_sustainable_yield

    At first, the population growth rate is fast, but it begins to slow as the population grows until it levels off to the maximum growth rate, after which it begins to decrease (figure 2). The equation for figure 2 is the differential of equation 1.1 ( Verhulst's 1838 growth model ): [ 13 ]

  4. Doubling time - Wikipedia

    en.wikipedia.org/wiki/Doubling_time

    For example, with an annual growth rate of 4.8% the doubling time is 14.78 years, and a doubling time of 10 years corresponds to a growth rate between 7% and 7.5% (actually about 7.18%). When applied to the constant growth in consumption of a resource, the total amount consumed in one doubling period equals the total amount consumed in all ...

  5. Relative growth rate - Wikipedia

    en.wikipedia.org/wiki/Relative_growth_rate

    However, we usually prefer to measure time in hours or minutes, and it is not difficult to change the units of time. For example, since 1 hour is 3 twenty-minute intervals, the population in one hour is () =. The hourly growth factor is 8, which means that for every 1 at the beginning of the hour, there are 8 by the end.

  6. Mean annual increment - Wikipedia

    en.wikipedia.org/wiki/Mean_annual_increment

    The mean annual increment (MAI) or mean annual growth refers to the average growth per year a tree or stand of trees has exhibited/experienced up to a specified age. For example, a 20-year-old tree that has a stem volume of 0.2 m 3 has an MAI of 0.01 m 3 /year.

  7. Periodic annual increment - Wikipedia

    en.wikipedia.org/wiki/Periodic_annual_increment

    Where: Y is the yield (volume, height, DBH, etc.) at times 1 and 2 and T 1 represents the year starting the growth period, and T 2 is the end year. Example: Say that the growth period is from age 5 to age 10, and the yield (height of the tree), is 14 feet at the beginning of the period and 34 feet at the end.

  8. Jaws ratio - Wikipedia

    en.wikipedia.org/wiki/Jaws_ratio

    The ratio is so named because, when these rates are graphed, the space between the lines resembles a pair of jaws. [1] Strictly speaking, the jaws ratio is not a true ratio in that the calculation is not expressed as one number divided by another, and is calculated as follows: Jaws ratio = (Income Growth Rate) − (Expense Growth Rate). The ...

  9. Ricker model - Wikipedia

    en.wikipedia.org/wiki/Ricker_model

    Bifurcation diagram of the Ricker model with carrying capacity of 1000. The Ricker model, named after Bill Ricker, is a classic discrete population model which gives the expected number N t+1 (or density) of individuals in generation t + 1 as a function of the number of individuals in the previous generation, [1]