The term monographia is derived from the Greek 'mono' (single) and grapho (to write), meaning writing on a single subject. Unlike a textbook, which surveys the state of knowledge in a field, the main purpose of a monograph is to present primary research and original scholarship.he term monographia is derived from the Greek 'mono' (single) and grapho (to write), meaning writing on a single subject. Unlike a textbook, which surveys the state of knowledge in a field, the main purpose of a monograph is to present primary research and original scholarship.
LEDs are âdirectionalâ light sources, which means they emit light in a specific direction, unlike incandescent and compact fluorescent bulbs, which emit light and heat in all directions. For this reason, LED lighting is able to use light and energy more efficiently in many applications.
Light-emitting diodes, or LEDs, are the new rock stars of the bulb world. When an LED is switched on, electrons and electron holes come together (and don't worry, I'm not completely sure I fully understand what a hole is in this context, either).