Temperature coefficientA temperature coefficient describes the relative change of a physical property that is associated with a given change in temperature. For a property R that changes when the temperature changes by dT, the temperature coefficient α is defined by the following equation: Here α has the dimension of an inverse temperature and can be expressed e.g. in 1/K or K−1. If the temperature coefficient itself does not vary too much with temperature and , a linear approximation will be useful in estimating the value R of a property at a temperature T, given its value R0 at a reference temperature T0: where ΔT is the difference between T and T0.
GyratorA gyrator is a passive, linear, lossless, two-port electrical network element proposed in 1948 by Bernard D. H. Tellegen as a hypothetical fifth linear element after the resistor, capacitor, inductor and ideal transformer. Unlike the four conventional elements, the gyrator is non-reciprocal. Gyrators permit network realizations of two-(or-more)-port devices which cannot be realized with just the conventional four elements. In particular, gyrators make possible network realizations of isolators and circulators.
Load factor (electrical)In electrical engineering the load factor is defined as the average load divided by the peak load in a specified time period. It is a measure of the utilization rate, or efficiency of electrical energy usage; a high load factor indicates that load is using the electric system more efficiently, whereas consumers or generators that underutilize the electric distribution will have a low load factor. An example, using a large commercial electrical bill: peak demand = 436kW use = 57200kWh number of days in billing cycle = 30day Hence: load factor = ( [ 57200kWh / {30day × 24h/d} ] / 436kW ) × 100% = 18.
Korotkoff soundsKorotkoff sounds are the sounds that medical personnel listen for when they are taking blood pressure using a non-invasive procedure. They are named after Nikolai Korotkov, a Russian physician who discovered them in 1905, when he was working at the Imperial Medical Academy in St. Petersburg, the Russian Empire. The sounds heard during the measurement of blood pressure are not the same as the heart sounds heard during chest auscultation that are due to vibrations inside the ventricles associated with the snapping shut of the valves.
