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The very ambiguous terms percent solution and percentage solutions with no other qualifiers continue to occasionally be encountered. In thermal engineering, vapor quality is used for the mass fraction of vapor in the steam. In alloys, especially those of noble metals, the term fineness is used for the mass fraction of the noble metal in the alloy.
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). For volume fraction, the suffix "V" or "v" is sometimes appended to the parts-per notation (e.g. ppmV, ppbv, pptv).
Intravenously, the LD 50 of potassium chloride is far smaller, at about 57.2 mg/kg to 66.7 mg/kg; this is found by dividing the lethal concentration of positive potassium ions (about 30 to 35 mg/kg) [34] by the proportion by mass of potassium ions in potassium chloride (about 0.52445 mg K + /mg KCl). [35]
For example, such a regulation might limit the concentration of NOx to 55 ppmv in a dry combustion exhaust gas corrected to 3 volume percent O 2. As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO 2.
Prophylaxis with perchlorate-containing water at concentrations of 17 ppm, corresponding to 0.5 mg/(kg·d) intake for a person of 70 kg consuming 2 litres of water per day, was found to reduce the baseline of radioiodine uptake by 67% [10] This is equivalent to ingesting a total of just 35 mg of perchlorate ions per day. In another related ...
For the drugs administered by oral and dermal route, the units of threshold dose are mg/kg body-weight/day (dose of the drug in mg per body weight in kg per day) or ppm (parts per million), while the threshold dose of drugs by inhalation delivery has the unit of mg/L 6h/day (amount of drug in mg in 1L of air, for 6 hours per day). [8]
Subsequently, the National Academy of Sciences (NAS) reviewed the health implications of perchlorate, and in 2005 proposed a much higher alternative reference dose of 0.0007 mg/kg/day based primarily on a 2002 study by Greer et al. [6] During that study, 37 adult human subjects were split into four exposure groups exposed to 0.007 (7 subjects ...
More precisely, the first number ("N value") is the percentage of elemental nitrogen by weight in the fertilizer; that is, the mass fraction of nitrogen times 100. The second number ("P value") is the percentage by weight of phosphorus pentoxide P 2 O 5. The third number ("K value") is the equivalent content of potassium oxide K 2 O. [3]