What Is Potassium? Potassium is a mineral that, among other things, helps muscles contract, helps regulate fluids and mineral balance in and out of body cells, and helps maintain normal blood pressure by blunting the effect of sodium. Potassium also may reduce the risk of recurrent kidney stones and bone loss as we age.
Racking strength, simply explained, is the ability of a square or rectangular (wall) area to maintain its shape under duress. The picture below (from an old federal document testing racking strength) demonstrates what can happens with stress exceeds a wall's racking strength.acking strength, simply explained, is the ability of a square or rectangular (wall) area to maintain its shape under duress. The picture below (from an old federal document testing racking strength) demonstrates what can happens with stress exceeds a wall's racking strength.
The ultimate racking strength of shear walls was reached at around or before the displacement of 20mm. Inthis study, the required minimum racking strength and minimum width for shear wall was proposed to be 500kgf and900mm, respectively. Racking resistance of shear walls decreased linearly as opening area increased.However, whenthe shear wall section left after opening cut is less than the required minimum width for shear wall, the racking resistancewas considerably less than the linear relationship between racking strength and opening area.or example, the required minimum racking is 500kgf for shear wall, then around 955mm can be obtained as the minimum width for shear walls from the equation for NB (SEC) (stabilized. envelope curve for specimens with no hold-down connector).