Self-employmentSelf-employment is the state of working for oneself rather than an employer. Tax authorities will generally view a person as self-employed if the person chooses to be recognised as such or if the person is generating income for which a tax return needs to be filed. In the real world, the critical issue for the tax authorities is not whether a person is engaged in a business activity (called "trading" even when referring to the provision of a service) but whether the activity is profitable and therefore potentially taxable.
CathodoluminescenceCathodoluminescence is an optical and electromagnetic phenomenon in which electrons impacting on a luminescent material such as a phosphor, cause the emission of photons which may have wavelengths in the visible spectrum. A familiar example is the generation of light by an electron beam scanning the phosphor-coated inner surface of the screen of a television that uses a cathode ray tube. Cathodoluminescence is the inverse of the photoelectric effect, in which electron emission is induced by irradiation with photons.
UnderemploymentUnderemployment is the underuse of a worker because a job does not use the worker's skills, is part-time, or leaves the worker idle. Examples include holding a part-time job despite desiring full-time work, and overqualification, in which the employee has education, experience, or skills beyond the requirements of the job. Underemployment has been studied from a variety of perspectives, including economics, management, psychology, and sociology. In economics, for example, the term underemployment has three different distinct meanings and applications.
