Search results
Results from the WOW.Com Content Network
Selenium is found in metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells.
Tests are described in Fitnesse as couplings of inputs and expected outputs. These couplings are expressed variations of a decision table.The FitNesse tool supports several of these variations, ranging from literal decision tables to tables that execute queries to tables that express testing scripts (i.e. a literal ordering of steps that must be followed to reach a result).
The first molar ionization energy applies to the neutral atoms. The second, third, etc., molar ionization energy applies to the further removal of an electron from a singly, doubly, etc., charged ion. For ionization energies measured in the unit eV, see Ionization energies of the elements (data page). All data from rutherfordium onwards is ...
In geometry, focuses or foci (/ ˈ f oʊ k aɪ /; sg.: focus) are special points with reference to which any of a variety of curves is constructed. For example, one or two foci can be used in defining conic sections , the four types of which are the circle , ellipse , parabola , and hyperbola .
Selenium dioxide is the chemical compound with the formula SeO 2. This colorless solid is one of the most frequently encountered compounds of selenium . It is used in making specialized glasses as well as a reagent in organic chemistry.
Selenous acid is easily formed upon the addition of selenium dioxide to water. As a crystalline solid, the compound can be seen as pyramidal molecules that are interconnected with hydrogen bonds. In solution it is a diprotic acid: [ 3 ]
Selenium is a component of the amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient that functions as cofactor for glutathione peroxidases and certain forms of thioredoxin reductase. [1] Selenium-containing proteins are produced from inorganic selenium via the intermediacy of selenophosphate (PSeO 3 3 ...
Component interface testing is a variation of black-box testing, with the focus on the data values beyond just the related actions of a subsystem component. [41] The practice of component interface testing can be used to check the handling of data passed between various units, or subsystem components, beyond full integration testing between ...