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This same classification is also used by the National Weather Service. The National Weather Service of Quad Cities use a modified EF scale wording, which gives a new term for each rating on the scale, going from weak to catastrophic. [55] The table shows other variations of the tornado rating classifications based on certain areas.
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water.Solutions of HF are colorless, acidic and highly corrosive.A common concentration is 49% (48-52%) but there are also stronger solutions (e.g. 70%) and pure HF has a boiling point near room temperature.
In their analysis, it was determined all three tornadoes caused damage well-beyond their assigned EF-scale ratings, with all three tornadoes having EF5-intensity winds. At the end of the analysis, the researchers stated, "the lofting wind speeds given by this model are much higher than the rating based on the ground survey EF-scale assessment.
Now, normally: either VHF or UHF; HF communications avionics are usually abbreviated simply HF CORSIA Carbon Offsetting and Reduction Scheme for International Aviation: COTS Commercial off-the-shelf: CPA Closest point of approach CPDLC controller–pilot data link communications: CPR Changed product rule EASA: CPS Cycles per second CRD
Buffered oxide etch (BOE), also known as buffered HF or BHF, is a wet etchant used in microfabrication. It is a mixture of a buffering agent, such as ammonium fluoride NH 4 F, and hydrofluoric acid (HF). Its primary use is in etching thin films of silicon nitride (Si 3 N 4) or silicon dioxide (SiO 2), by the reaction:
Fluorocarbons with few C–F bonds behave similarly to the parent hydrocarbons, but their reactivity can be altered significantly.For example, both uracil and 5-fluorouracil are colourless, high-melting crystalline solids, but the latter is a potent anti-cancer drug.
Sectional charts are in 1:500,000 scale and are named for a city on the map. The Federal Aviation Administration (FAA) in the United States publishes over 50 charts covering the continental United States, Alaska, and Hawaii. Sectional charts are published by the National Aeronautical Navigation Services Group of the FAA.
Under the Köppen climate classification, the ice cap climate is denoted as EF. Ice caps are defined as a climate with no months having a mean temperature above 0 °C (32 °F). [ 2 ] Such areas are found around the north and south pole, and on the top of many high mountains.