General

Porosity and Permeability: Definition and Types

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porosity

Porosity is the percentage of the bulk volume of a rock or soil that is occupied by interstices, whether isolated or connected. Effective porosity is the percent of the total volume of a given mass of soil or rock that consists of interconnected interstices. Types of Porosity Primary porosity is the porosity that developed during … Read more

Why gold is so costly and precious to mankind?

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Gold is a precious metal. Gold was used by almost all the major civilizations in the world. For most culture, both past and present, it has been of a great economic importance. Gold has historically been the only universally accepted medium of exchange. What makes gold so valuable? The most important is its rarity, although … Read more