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For the SLAP (Standard Light Antarctic Precipitation) standard that determines the isotopic composition of natural water from the Antarctic, the concentration of deuterium is 89.02 ppm. [6] Snow water, especially from glacial mountain meltwater, is significantly lighter than ocean water. Glacier analysis at 22,000-24,000 of Mount Everest have ...
The recent measurement of deuterium amounts of 161 atoms per million hydrogen in Comet 103P/Hartley (a former Kuiper belt object), a ratio almost exactly that in Earth's oceans (155.76 ± 0.1, but in fact from 153 to 156 ppm), emphasizes the theory that Earth's surface water may be largely from comets.
Heavy water is less dissociated than light water at given temperature, and the true concentration of D + ions is less than H + ions would be for light water at the same temperature. The same is true of OD − vs. OH − ions. For heavy water Kw D 2 O (25.0 °C) = 1.35 × 10 −15, and [D + ] must equal [OD − ] for neutral water
In the laboratory it is produced by treating sodium hydride with deuterated water: [1] NaH + D 2 O → HD + NaOD. Hydrogen deuteride is a minor component of naturally occurring molecular hydrogen. It is one of the minor but noticeable components of the atmospheres of all the giant planets, with abundances
Yet another nontrivial prediction of the IsoRes hypothesis is that at ≈250-350 ppm deuterium content, the terrestrial resonance becomes “perfect”, and the rates of biochemical reactions and growth of terrestrial organisms further increase. This prediction seems to be matched by at least some experimental observations. [8] [9]
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.
The Ordovician and Silurian black shales have a background uranium content of 40 to 60 ppm. However, hydrothermal and supergene processes caused remobilsation and enrichment of the uranium. The production between 1950 and 1990 was about 100,000 t of uranium at average grades of 700 to 1,000 ppm.
Two humans exposed to 2.9 ppm TeCA for 30 minutes showed symptoms of vomiting and nausea. [17] These symptoms also caused weight loss. [32] A study by Horiuchi et al. [33] showed that a monkey frequently exposed to 1.9 ppm TeCA got anorexic and developed regular diarrhea.