Power measurements classifications, other

The concepts of acidity and basicity are used by scientists from all branches of theoretical, experimental, and engineering chemistry. They are fundamental in nature and are of unquestionable utility as a powerful classification tool. However, it is interesting to observe that the meaning of these two simple words may vary depending on the compounds or materials discussed, experimental conditions or methods of study, particular applications, state of matter or size of particles, and, in some instances, even the context in which the terms are used. Indeed, any discussion about acid-base properties is an assertion in comparative terms a debate about relativity. By definition, acidity and basicity are opposite properties (or principles) that manifest themselves only in relationship to each other. Acids are revealed and measured by bases the presence of bases is revealed and quantified by acids. 

The sensors employed in wearable body sensor network systems can be divided into active sensors and passive sensors. There is ambiguity in the classification, and many authors are using the other way around. In the biomedical measurement field, however, the definition of sensor type follows the convention of other electronic instrumentation fields the active sensors are those sensors that require an external power source to convert the input into a usable output signal, while passive sensors are those that intrinsically provide their own energy or derive energy from the phenomenon being... 

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