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Where HV is the hydroxyl value; V B is the amount (ml) potassium hydroxide solution required for the titration of the blank; V acet is the amount (ml) of potassium hydroxide solution required for the titration of the acetylated sample; W acet is the weight of the sample (in grams) used for acetylation; N is the normality of the titrant; 56.1 is ...
The yield of ethylene oxide is about 80% of the theoretical value; for 1 tonne (0.98 long tons; 1.1 short tons) of ethylene oxide, about 200 kg (440 lb) of ethylene dichloride is produced. [68] But, the major drawbacks of this process are high chlorine consumption and effluent load.
An example of the Hell–Volhard–Zelinsky reaction can be seen in the preparation of alanine from propionic acid.In the first step, a combination of bromine and phosphorus tribromide is used in the Hell–Volhard–Zelinsky reaction to prepare 2-bromopropionic acid, [3] which in the second step is converted to a racemic mixture of the amino acid product by ammonolysis.
The Vickers hardness test was developed in 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials. [1] The Vickers test is often easier to use than other hardness tests since the required calculations are independent of the size of the indenter, and the indenter ...
In the very first study about the dangers of vinyl chloride, published by Patty in 1930, it was disclosed that exposure of test animals to just a single short-term high dose of vinyl chloride caused liver damage. [31] In 1949, a Russian publication discussed the finding that vinyl chloride caused liver injury among workers. [32]
[1] For a fuel of composition C c H h O o N n , the (higher) heat of combustion is 419 kJ/mol × ( c + 0.3 h − 0.5 o ) usually to a good approximation (±3%), [ 2 ] [ 3 ] though it gives poor results for some compounds such as (gaseous) formaldehyde and carbon monoxide , and can be significantly off if o + n > c , such as for glycerine ...
For tungsten, (1 − ~)A 0 = (0.6 to 1.0) × 10 6 A⋅m −2 ⋅K −2, and ϕ = 4.52 eV. At 2500 °C, the emission is 28207 A/m 2 . The emission current as given above is many times greater than that normally collected by the electrodes, except in some pulsed valves such as the cavity magnetron .
A 2010 review study by Puren et al. [2] categorizes viral load testing into three types: (1) nucleic acid amplification based tests (NATs or NAATs) commercially available in the United States with Food and Drug Administration (FDA) approval, or on the market in the European Economic Area (EEA) with the CE marking; (2) "Home–brew" or in-house NATs; (3) non-nucleic acid-based test.