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Elevator puzzle

Early exposure assessments focused on diet and in particular hsh that had elevated concentrations relative to other animal products (Kiviranta et al, 2004 Ohta et al, 2002). These assessments were informed by our experience with PCBs and PCDD/F for which diet was clearly the main exposure route. The exposure assessments pointed to a missing source since dietary intake of PBDEs did not seem to account for some elevated levels being measured in breast milk or blood serum. A particular puzzle was the source of PBDEs to the few women with up to 1000 times higher concentrations in their breast milk relative to others. For example, Ryan (2004) reported that concentrations from 98 Canadian women ranged from 23 to 38 240ng/kg whole milk with an arithmetic mean and median of 2400 and 880ng/kg whole milk. Another puzzle was the tenfold... [Pg.258]

Solutes affect some of the physical properties of their solvents. Early researchers were puzzled to discover that the effects of a solute on a solvent depended only on how many solute particles were in solution, not on the specific solute dissolved. Physical properties of solutions that are affected by the number of particles but not the identity of dissolved solute particles are called colligative properties. The word colligative means depending on the collection. Colligative properties include vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure. [Pg.471]

It was usually men who asked me why I did it. Some were amused, others puzzled. I didn t mind the jokes in the newspaper office where I worked about whether I left the building by window, roof or in the elevator. The truth is that I was an unlikely person to jump out of an airplane, being neither graceful, daring nor self-possessed. I had a bad back, uncertain ankles and could not drive with competence because of deficient depth perception and a fear of all buses coming toward me. A friend joked that if I broke any bones I would have to be shot because I would never mend. [Pg.602]

It has already been mentioned that, if the surface deformation is due to buoyancy-driven thermal convection alone, the surface must be convex at the cell centers. Such behavior was observed by Spangenberg and Rowland (SIO) for deep layers of evaporating water. Furthermore, in a repetition of one of Benard s experiments, i.e., using approximately 1-mm-thick layers of melted wax, these authors obtained the puzzling result that in these systems the elevation also occurred above the cell centers. [Pg.114]

Early investigators were puzzled by experiments in which certain substances depressed the freezing point or elevated the boiling point of a solvent more than expected. For example, a 0.1 m solution of sodium chloride, NaCl, lowers the freezing point of the solvent nearly twice as much as a 0.1 m solution of sucrose. A 0.1 m solution of calcium chloride, CaCl2, lowers the freezing point of the solvent nearly three times as much as a 0.1 m solution of sucrose. The effect on boiling points is similar. [Pg.429]


See other pages where Elevator puzzle is mentioned: [Pg.75]    [Pg.237]    [Pg.170]    [Pg.232]    [Pg.418]    [Pg.213]    [Pg.192]    [Pg.604]    [Pg.584]    [Pg.211]    [Pg.445]    [Pg.19]    [Pg.747]    [Pg.139]    [Pg.453]    [Pg.318]    [Pg.23]    [Pg.13]   
See also in sourсe #XX -- [ Pg.310 ]




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