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  2. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    One part per billion (ppb) denotes one part per 1,000,000,000 (10 9) parts, and a value of 10 −9. This is equivalent to about three seconds out of a century. One part per trillion (ppt) denotes one part per 1,000,000,000,000 (10 12) parts, and a value of 10 −12. This is equivalent to about thirty seconds out of every million years.

  3. Ion chromatography - Wikipedia

    en.wikipedia.org/wiki/Ion_chromatography

    Ion Exchange Resins(IER) have been widely used especially in medicines due to its high capacity and the uncomplicated system of the separation process. One of the synthetic uses is to use Ion Exchange Resins for kidney dialysis. This method is used to separate the blood elements by using the cellulose membraned artificial kidney. [56]

  4. Excess property - Wikipedia

    en.wikipedia.org/wiki/Excess_property

    By definition, excess properties are related to those of the ideal solution by: z E = z − z IS {\displaystyle z^{E}=z-z^{\text{IS}}} Here, the superscript IS denotes the value in the ideal solution, a superscript E {\displaystyle E} denotes the excess molar property, and z {\displaystyle z} denotes the particular property under consideration.

  5. Exchange current density - Wikipedia

    en.wikipedia.org/wiki/Exchange_current_density

    The exchange current density depends critically on the nature of the electrode, not only its structure, but also physical parameters such as surface roughness. Of course, factors that change the composition of the electrode, including passivating oxides and adsorbed species on the surface, also influence the electron transfer.

  6. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    This glossary of chemistry terms is a list of terms and definitions relevant to chemistry, including chemical laws, diagrams and formulae, laboratory tools, glassware, and equipment. Chemistry is a physical science concerned with the composition, structure, and properties of matter , as well as the changes it undergoes during chemical reactions ...

  7. Use value - Wikipedia

    en.wikipedia.org/wiki/Use_value

    Use-value as an aspect of the commodity coincides with the physical palpable existence of the commodity. Wheat, for example, is a distinct use-value differing from the use-values of cotton, glass, paper, etc. A use-value has value only in use, and is realized only in the process of consumption. One and the same use-value can be used in various ...

  8. High-performance liquid chromatography - Wikipedia

    en.wikipedia.org/wiki/High-performance_liquid...

    Many different types of columns are available, filled with adsorbents varying in particle size, porosity, and surface chemistry. The use of smaller particle size packing materials requires the use of higher operational pressure ("backpressure") and typically improves chromatographic resolution (the degree of peak separation between consecutive ...

  9. Exchange value - Wikipedia

    en.wikipedia.org/wiki/Exchange_value

    a value, represented by the socially necessary labour time to produce it (Note: the first link is to a non-Marxian definition of value); a use value (or utility); an exchange value, which is the proportion at which a commodity can be exchanged for other entities; a price (an actual selling price, or an imputed ideal price).