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The decibel originates from methods used to quantify signal loss in telegraph and telephone circuits. Until the mid-1920s, the unit for loss was miles of standard cable (MSC). 1 MSC corresponded to the loss of power over one mile (approximately 1.6 km) of standard telephone cable at a frequency of 5000 radians per second (795.8 Hz), and matched closely the smallest attenuation detectable to a ...
For example, in the 1930s Widmark measured alcohol and blood by mass, and thus reported his concentrations in units of g/kg or mg/g, weight alcohol per weight blood. Blood is denser than water and 1 mL of blood has a mass of approximately 1.055 grams, thus a mass-volume BAC of 1 g/L corresponds to a mass-mass BAC of 0.948 mg/g.
During fermentation, the yeasts consume the sugars and produce alcohol. The density of sugar in water is greater than the density of alcohol in water. A hydrometer is used to measure the change in specific gravity (SG) of the solution before and after fermentation. The volume of alcohol in the solution can then be estimated.
It is first determined whether M is indeed greater than 1.0 by calculating M from the subsonic equation. If M is greater than 1.0 at that point, then the value of M from the subsonic equation is used as the initial condition for fixed point iteration of the supersonic equation, which usually converges very rapidly. [8]
However, the effect only affects alloys with more than 0.8% Mg2Si (excluding Mg or Si surpluses) and alloys with more than 0.6% Mg2Si if Mg or Si surpluses are present. To prevent these negative effects, AlMgSi can be annealed after quenching at 80 °C for 5–30 minutes, which stabilizes the material condition and temporarily does not change.
The sone (/ ˈ s oʊ n /) is a unit of loudness, the subjective perception of sound pressure.The study of perceived loudness is included in the topic of psychoacoustics and employs methods of psychophysics.
The point was first established by the Milanese typographer, Francesco Torniella da Novara (c. 1490 – 1589) in his 1517 alphabet, L'Alfabeto.The construction of the alphabet is the first based on logical measurement called "Punto," which corresponds to the ninth part of the height of the letters or the thickness of the principal stroke.
However, this view has little mathematical basis, as rank correlation coefficients measure a different type of relationship than the Pearson product-moment correlation coefficient, and are best seen as measures of a different type of association, rather than as an alternative measure of the population correlation coefficient. [7] [8]