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Measured values for actual systems will always be significantly less than these theoretical maxima. In Europe, the standard test conditions for ground source heat pump units use 308 K (35 °C; 95 °F) for and 273 K (0 °C; 32 °F) for . According to the above formula, the maximum theoretical COPs would be
c °C to f °F: f = c × 1.8 + 32; f °F to k K: k = f + 459.67 / 1.8 k K to f °F: f = k × 1.8 − 459.67; There is also an exact conversion between Celsius and Fahrenheit scales making use of the correspondence −40 °F ≘ −40 °C. Again, f is the numeric value in degrees Fahrenheit, and c the numeric value in degrees Celsius: f ...
Its initial value is 1 (when v = 0); and as velocity approaches the speed of light (v → c) γ increases without bound (γ → ∞). α (Lorentz factor inverse) as a function of velocity—a circular arc. In the table below, the left-hand column shows speeds as different fractions of the speed of light (i.e. in units of c). The middle column ...
In radio astronomy, the unit of electromagnetic flux is the jansky (symbol Jy), equivalent to 10 −26 watts per square metre per hertz (= 10 −26 kg/s 2 in base units, about 8.8×10 −31 BTU/ft 2). It is named after the pioneering radio astronomer Karl Jansky. The brightest natural radio sources have flux densities of the order of one to one ...
GNU Units version 2.19 was released on 31 May 2019, to reflect the 2019 revision of the SI; Version 2.14 released on 8 March 2017 fixed several minor bugs and improved support for building on Windows. Version 2.10, released on 26 March 2014, added support for rational exponents greater than one, and added the ability to save an interactive ...
drag force F d. Using the algorithm of the Buckingham π theorem, these five variables can be reduced to two dimensionless groups: drag coefficient c d and; Reynolds number Re. That this is so becomes apparent when the drag force F d is expressed as part of a function of the other variables in the problem:
There are more detailed generalized compressibility factor graphs based on as many as 25 or more different pure gases, such as the Nelson-Obert graphs. Such graphs are said to have an accuracy within 1–2 percent for values greater than 0.6 and within 4–6 percent for values of 0.3–0.6.
In thermodynamics, the phase rule is a general principle governing multi-component, multi-phase systems in thermodynamic equilibrium.For a system without chemical reactions, it relates the number of freely varying intensive properties (F) to the number of components (C), the number of phases (P), and number of ways of performing work on the system (N): [1] [2] [3]: 123–125