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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.
Modalities applied to measurement of ejection fraction is an emerging field of medical mathematics and subsequent computational applications. The first common measurement method is echocardiography, [7] [8] although cardiac magnetic resonance imaging (MRI), [8] [9] cardiac computed tomography, [8] [9] ventriculography and nuclear medicine (gated SPECT and radionuclide angiography) [8] [10 ...
The idea to give each band a number, in which the number is the logarithm of the approximate geometric mean of the upper and lower band limits in Hz, originated with B. C. Fleming-Williams, who suggested it in a letter to the editor of Wireless Engineer in 1942. For example, the approximate geometric mean of band 7 is 10 MHz, or 10 7 Hz.
HF's position in the electromagnetic spectrum. High frequency (HF) is the ITU designation [1] [2] for the band of radio waves with frequency between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one hundred meters).
Heart failure with recovered ejection fraction (HFrecovEF or HFrecEF): patients previously with HFrEF with complete normalization of left ventricular ejection (≥50%). [64] [65] Heart failure may also be classified as acute or chronic. Chronic heart failure is a long-term condition, usually kept stable by the treatment of symptoms.
The primary HFGCS voice frequencies are 4724.0 kHz, 8992.0 kHz, 11175.0 kHz, and 15016.0 kHz. In addition to the HFGCS, U.S. aircraft frequently use Military Auxiliary Radio System (MARS) HF stations (13927.0 kHz) and Canadian Forces HF stations (11232.0 kHz) to relay messages. Various other discrete frequencies are available, and used, as part ...
There is high uncertainty regarding correlations between long-term, low-level exposure to ELF fields and a number of health effects, including leukemia in children. In October 2005, WHO convened a task group of scientific experts to assess any risks to health that might exist from "exposure to ELF electric and magnetic fields in the frequency ...
This is defined as a left ventricular ejection fraction (LVEF) of 40% or less. About half of heart failure patients have a reduced ejection fraction. [2] Other types of heart failure are heart failure with mildly reduced ejection fraction (LVEF between 40% and 50%) and heart failure with preserved ejection fraction (LVEF 50% or higher). [1] [3]