CONVERSIONS                                                        Return to table of contents

 

231 cubic inches = 1 gallon.

2.31 feet of water = 1 pound per square inch.

1.55 cubic feet per second  =  1 MGD.

.746 kW = 1 HP.

1.34 HP = 1 kW.

1 gallon of water weighs 8.34 pounds.

1 cubic foot will contain 7.48 gallons of Mercury, or sulfuric acid.

1 gallon of saturated brine holds 2.48 pounds of salt.

1 cubic foot of saturated brine holds 18.6 pounds of salt.

1 gallon of fresh water will dissolve 2.7 pounds of salt.

1 gallon of water will make 1.2 gallons of saturated brine.

1 cubic foot of dry salt will weigh about 70 pounds (varies with moisture content and size of crystals).

1 grain per gallon equals 17.1 parts per million (ppm) or 17.1 mg/L.

Hardness:

Total hardness and capacity are always in terms of calcium carbonate.

Convert:

NaCl    to    CaCO₃       multiply by              0.856

Ca       to    CaCO₃       multiply by              2.5

Mg       to    CaCO₃       multiply by              4.115

Na       to    CaCO₃        multiply by           2.18

 

One googol = 10¹⁰⁰ or, 

One googolplex = 10^googol or , if you used a nucleon to represent each zero there would not be enough nucleons in the entire known universe to write out a googolplex. 

 

The Skewes’ number is reputed to be the largest number that has occurred in a mathematical proof .

AVOGADRO’S NUMBER

          The number equal to the number of Carbon atoms in exactly 12 grams of

            pure ¹²C.  This number is called Avogadro’s number. It is 6.02 x 10²³.

Approximate rules of thumb

At 1800 rpm, a motor develops 3 ft-lb per hp.

At 1200 rpm, a motor develops 4.5 ft-lb per hp

At 460 volts, a 3 phase motor draws 1.25 amps per hp.

HP = (torque x rpm)/5250

rpm = (120 x Frequency)/number of poles

          FORMULAS

 

 

 

           Mean value,  , Arithmetic Mean, [dividend of the sum of the elements],

 

          Variance, ,

 

Standard Deviation,  ,

 

Geometric Mean     ,  [n^th  root of the product of the elements].

 

Relative Percent Difference  ,

                        Where “D₁” is the first result in the duplicate pair, “D₂” the second.  The vertical brackets mean absolute value.

  ,

 

 

,

 

,

 

 

 

 

,

 

,

 

 

 

Concentration (molarity, dilution)

               

              

                          

                              

            

            

             .

where: C_u = measured concentration of the unknown sample                                                                          V_u = volume of the unknown sample

                                                                                              C_s = concentration of the standard

                                                                                              V_s = volume of the standard.

             where: X_s = measured value of the spiked sample

X_u = measured value for the unspiked sample adjusted for the dilution of the spike volume

                                                                                            K = known value of the spike in the sample.

                    

 

,

 

,

 

,

 

,

 

,

 

,

 

 

,

 

,

 

,

 

,

 

,

 

Mean Cell Residence Time

                 ,

 

,

 

,

Pipe volume, flow rate, flushing time.  (Sampling techniques).

 

          ,

 

          ,

 

          ,

         ,

 

 

 

,

 

,

 

,

 

,

 

,