enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. T wave - Wikipedia

    en.wikipedia.org/wiki/T_wave

    T wave is considered flat when the wave varies from -1.0 mm to + 1.0 mm in height. Hypokalemia or digitalis therapy can cause flattened T wave with a prominent U wave. As hypokalemia progressively worsens, the T wave becomes more flattened while the U wave becomes more prominent, with progressively deeper ST segment depression.

  3. U band - Wikipedia

    en.wikipedia.org/wiki/U_band

    The U band is a range of frequencies contained in the microwave region of the electromagnetic spectrum. Common usage places this range between 40 and 60 GHz , but may vary depending on the source using the term.

  4. Time–frequency analysis - Wikipedia

    en.wikipedia.org/wiki/Time–frequency_analysis

    In signal processing, time–frequency analysis comprises those techniques that study a signal in both the time and frequency domains simultaneously, using various time–frequency representations. Rather than viewing a 1-dimensional signal (a function, real or complex-valued, whose domain is the real line) and some transform (another function ...

  5. Radio spectrum - Wikipedia

    en.wikipedia.org/wiki/Radio_spectrum

    As frequency increases above 30 GHz (the beginning of the millimeter wave band), atmospheric gases absorb increasing amounts of power, so the power in a beam of radio waves decreases exponentially with distance from the transmitting antenna. At 30 GHz, useful communication is limited to about 1 km, but as frequency increases the range at which ...

  6. Letter frequency - Wikipedia

    en.wikipedia.org/wiki/Letter_frequency

    The California Job Case was a compartmentalized box for printing in the 19th century, sizes corresponding to the commonality of letters. The frequency of letters in text has been studied for use in cryptanalysis, and frequency analysis in particular, dating back to the Arab mathematician al-Kindi (c. 801–873 AD), who formally developed the method (the ciphers breakable by this technique go ...

  7. U wave - Wikipedia

    en.wikipedia.org/wiki/U_wave

    The U wave is a wave on an electrocardiogram (ECG). It comes after the T wave of ventricular repolarization and may not always be observed as a result of its small size. 'U' waves are thought to represent repolarization of the Purkinje fibers. [1] [2] However, the exact source of the U wave remains unclear. The most common theories for the ...

  8. List of equations in wave theory - Wikipedia

    en.wikipedia.org/wiki/List_of_equations_in_wave...

    The phase velocity is the rate at which the phase of the wave propagates in space. The group velocity is the rate at which the wave envelope, i.e. the changes in amplitude, propagates. The wave envelope is the profile of the wave amplitudes; all transverse displacements are bound by the envelope profile.

  9. Frequency - Wikipedia

    en.wikipedia.org/wiki/Frequency

    The period (symbol T) is the interval of time between events, so the period is the reciprocal of the frequency: T = 1/f. [2] Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals , radio waves, and light.