Search results
Results From The WOW.Com Content Network
It is useful as a theoretical reference; an illuminant that gives equal weight to all wavelengths. It also has equal CIE XYZ tristimulus values, thus its chromaticity coordinates are (x,y)=(1/3,1/3). This is by design; the XYZ color matching functions are normalized such that their integrals over the visible spectrum are the same. [1]
Selenite, satin spar, desert rose, and gypsum flower are crystal habit varieties of the mineral gypsum.. All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning that it has two molecules of water), with the chemical formula CaSO 4 ·2H 2 O. Selenite contains no selenium, the similar names both derive from Greek selḗnē (σελήνη 'Moon').
James C. Maxwell's unification of the equations governing electricity, magnetism, and light in the late 19th century led to experiments on the interaction of light and matter. Some of these experiments had aspects which could not be explained until quantum mechanics emerged in the early part of the 20th century.
The accounting equation is a statement of equality between the debits and the credits. The rules of debit and credit depend on the nature of an account. For the purpose of the accounting equation approach, all the accounts are classified into the following five types: assets, capital, liabilities, revenues/incomes, or expenses/losses.
Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula C 6 H 5 OH. [5] It is a white crystalline solid that is volatile . The molecule consists of a phenyl group ( −C 6 H 5 ) bonded to a hydroxy group ( −OH ).
By 250 °C (482 °F), copious amounts of formaldehyde have been found to be produced by all silicones (1,200 to 4,600 μg CH 2 O/(g·hr)). [ 38 ] Some persons have been found to develop silicone allergies or extreme sensitivity [ 39 ] particularly after prolonged exposure to certain types of silicone products such as cosmetics, medical ...
View from the Window at Le Gras 1826 or 1827, believed to be the earliest surviving camera photograph. [1] Original (left) and colorized reoriented enhancement (right).. The history of photography began with the discovery of two critical principles: The first is camera obscura image projection; the second is the discovery that some substances are visibly altered by exposure to light. [2]