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  2. Power factor - Wikipedia

    en.wikipedia.org/wiki/Power_factor

    The power factor in a single-phase circuit (or balanced three-phase circuit) can be measured with the wattmeter-ammeter-voltmeter method, where the power in watts is divided by the product of measured voltage and current. The power factor of a balanced polyphase circuit is the same as that of any phase. The power factor of an unbalanced ...

  3. Per-unit system - Wikipedia

    en.wikipedia.org/wiki/Per-unit_system

    The base power value is the same for the entire power system of concern. The ratio of the voltage bases on either side of a transformer is selected to be the same as the ratio of the transformer voltage ratings. With these two rules, a per-unit impedance remains unchanged when referred from one side of a transformer to the other.

  4. Rate pressure product - Wikipedia

    en.wikipedia.org/wiki/Rate_pressure_product

    The calculation formula is: Rate Pressure Product (RPP) = Heart Rate (HR) * Systolic Blood Pressure (SBP) The units for the Heart Rate are beats per minute and for the Blood Pressure mmHg . Rate pressure product is a measure of the stress put on the cardiac muscle based on the number of times it needs to beat per minute (HR) and the arterial ...

  5. Mathematics of three-phase electric power - Wikipedia

    en.wikipedia.org/wiki/Mathematics_of_three-phase...

    The plotted line represents the variation of instantaneous voltage (or current) with respect to time. This cycle repeats with a frequency that depends on the power system. In electrical engineering, three-phase electric power systems have at least three conductors carrying alternating voltages that are offset in time by one-third of the period ...

  6. Atkinson resistance - Wikipedia

    en.wikipedia.org/wiki/Atkinson_resistance

    One gaul is defined as the resistance of an airway which, when air (of density 1.2 kg/m 3) flows along it at a rate of one cubic metre per second, causes a pressure drop of one pascal. The gaul has units of N·s 2 /m 8, or alternatively Pa·s 2 /m 6. It uses the same basic equation as its Imperial counterpart, but with slightly different ...

  7. Murray's law - Wikipedia

    en.wikipedia.org/wiki/Murray's_law

    Poiseuille flow in a cylinder of diameter h; the velocity field at height y is u(y).. Murray's original derivation uses the first set of assumptions described above. She begins with the Hagen–Poiseuille equation, which states that for fluid of dynamic viscosity μ, flowing laminarly through a cylindrical pipe of radius r and length l, the volumetric flow rate Q associated with a pressure ...

  8. Mean arterial pressure - Wikipedia

    en.wikipedia.org/wiki/Mean_arterial_pressure

    Mean arterial pressure can be measured directly or estimate from systolic and diastolic blood pressure by using a formula. [5] The least invasive method is the use of a blood pressure cuff which gives the values to calculate an estimate of the mean pressure. A similar method is to use a oscillometric blood pressure device that works by a cuff ...

  9. Power-voltage curve - Wikipedia

    en.wikipedia.org/wiki/Power-voltage_curve

    Power-voltage curve (also P-V curve) describes the relationship between the active power delivered to the electrical load and the voltage at the load terminals in an electric power system under a constant power factor. [1] When plotted with power as a horizontal axis, the curve resembles a human nose, thus it is sometimes called a nose curve. [2]