enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    The difference is quite significant when dealing with gases, and it is very important to specify which quantity is being used. For example, the conversion factor between a mass fraction of 1 ppb and a mole fraction of 1 ppb is about 4.7 for the greenhouse gas CFC-11 in air (Molar mass of CFC-11 / Mean molar mass of air = 137.368 / 28.97 = 4.74 ...

  3. Useful conversions and formulas for air dispersion modeling

    en.wikipedia.org/wiki/Useful_conversions_and...

    0.1 × ( 12 ÷ 8 ) = 0.15 grain per dscf when corrected to a gas having a specified reference CO 2 content of 12 volume %. Notes: Although ppmv and grains per dscf have been used in the above examples, concentrations such as ppbv (i.e., parts per billion by volume), volume percent, grams per dscm and many others may also be used.

  4. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    1 volume percent = 10,000 ppmv (i.e., parts per million by volume) with a million being defined as 10 6. Care must be taken with the concentrations expressed as ppbv to differentiate between the British billion which is 10 12 and the USA billion which is 10 9 (also referred to as the long scale and short scale billion, respectively).

  5. Molar concentration - Wikipedia

    en.wikipedia.org/wiki/Molar_concentration

    Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. [1] For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase : [2]

  6. Talk:Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Talk:Parts-per_notation

    The examples don't seem to be too accurate. A drop is usually defined as 0.05 ml, which then gives;. 1 drop in 50 ml = 1‰, 50ml is a very small cup 1 drop in 50 l = 1ppm 50 l is about 11 gallons, not 40 1 drop in 50 cubic metres = 1 ppb 1 drop = 1ppt, a 50 m swimming pool is 50*25*2 = 2,500 m^3 1 drop in 50,000,000 cubic metres = 1ppq, 50,000,000 m^3 is equivalent to a lake covering a square ...

  7. Total organic carbon - Wikipedia

    en.wikipedia.org/wiki/Total_organic_carbon

    A variation described as "membrane conductometric detection can allow for measurement of TOC across a wide analytical range in both deionized and non-deionized water samples. Modern high-performance TOC instruments are capable of detecting carbon concentrations well below 1 μg/L (1 part per billion or ppb).

  8. National Ambient Air Quality Standards - Wikipedia

    en.wikipedia.org/wiki/National_Ambient_Air...

    75 ppb 1-hour 99th Percentile of 1-hour daily maximum concentrations, averaged over 3 years 40 CFR 50.17: Secondary 0.5 ppm (1,300 μg/m 3) 3-hour Not to be exceeded more than once per year 40 CFR 50.5: Particulate matter (PM 10) Primary and Secondary 150 μg/m 3: 24-hour Not to be exceeded more than once per year on average over 3 years 40 CFR ...

  9. 5-Methylchrysene - Wikipedia

    en.wikipedia.org/wiki/5-Methylchrysene

    Indoor air particulate samples (<10 um) were collected in Chinese homes from Xuan Wei county burning smokey coal, smokeless coal, and wood in 1983 and 1984; the concentration of 5-methylchrysene was 1.6 to 17 ug/m 3, 0.21 to 3.5 ug/m 3, and 0.03 to 0.05 ug/m 3, respectively. Sampling was conducted in March and September, 2011.