Bureaucrats, emailconfirmed, Administrators
5,668
edits
GMU:Bioelectronics, aesthetics and other interesting things/Crystal radio: Difference between revisions
GMU:Bioelectronics, aesthetics and other interesting things/Crystal radio (view source)
Revision as of 23:09, 25 April 2016
, 25 April 2016→Conductors, insulators, semiconductors and other interesting things
| Line 33: | Line 33: | ||
* Silicate, or silicic acid (H4SiO4), is an important nutrient in the ocean. Unlike the other major nutrients such as phosphate, nitrate, or ammonium, which are needed by almost all marine plankton, silicate is an essential chemical requirement for very specific biota, including diatoms, radiolaria, silicoflagellates, and siliceous sponges. These organisms extract dissolved silicate from open ocean surface waters for the buildup of their particulate silica (SiO2), or opaline, skeletal structures (i.e. the biota’s hard parts). | * Silicate, or silicic acid (H4SiO4), is an important nutrient in the ocean. Unlike the other major nutrients such as phosphate, nitrate, or ammonium, which are needed by almost all marine plankton, silicate is an essential chemical requirement for very specific biota, including diatoms, radiolaria, silicoflagellates, and siliceous sponges. These organisms extract dissolved silicate from open ocean surface waters for the buildup of their particulate silica (SiO2), or opaline, skeletal structures (i.e. the biota’s hard parts). | ||
Biogenic silica (bSi) forms one of the most widespread biogenic minerals. For example, microscopic particles of silica can be found in bacteria, animals and plants. In order to conduct voltage for his bacterial radio Joe Davis used orange marine puffball sponges (Tethya aurantia). Silica is an amorphous metal oxide formed by complex inorganic polymerization processes. | |||
* Biogenic silica (bSi) forms one of the most widespread biogenic minerals. For example, microscopic particles of silica can be found in bacteria, animals and plants. In order to conduct voltage for his bacterial radio Joe Davis used orange marine puffball sponges (Tethya aurantia). Silica is an amorphous metal oxide formed by complex inorganic polymerization processes. | |||
* A semiconductor is a material with electrical conductivity due to electron flow (as opposed to ionic conductivity) intermediate in magnitude between that of a conductor and an insulator. Common semiconducting materials are crystalline solids. These include hydrogenated amorphous silicon and mixtures of arsenic, selenium and tellurium in a variety of proportions. Such compounds share with better known semiconductors intermediate conductivity and a rapid variation of conductivity. The electronic properties and the conductivity of a semiconductor can be changed in a controlled manner by adding very small quantities of other elements, called “dopants”, to the intrinsic material. In crystalline silicon typically this is achieved by adding impurities of boron or phosphorus to the melt | * A semiconductor is a material with electrical conductivity due to electron flow (as opposed to ionic conductivity) intermediate in magnitude between that of a conductor and an insulator. Common semiconducting materials are crystalline solids. These include hydrogenated amorphous silicon and mixtures of arsenic, selenium and tellurium in a variety of proportions. Such compounds share with better known semiconductors intermediate conductivity and a rapid variation of conductivity. The electronic properties and the conductivity of a semiconductor can be changed in a controlled manner by adding very small quantities of other elements, called “dopants”, to the intrinsic material. In crystalline silicon typically this is achieved by adding impurities of boron or phosphorus to the melt | ||