Search results
Results from the WOW.Com Content Network
Half-life (symbol t½) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential (or, rarely ...
Fracking (also known as hydraulic fracturing, fracing, hydrofracturing, or hydrofracking) is a well stimulation technique involving the fracturing of formations in bedrock by a pressurized liquid.
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
1.8 ks: The time slot for the typical situation comedy on television with advertisements included 2.28 ks: The duration of the Anglo-Zanzibar War, the shortest war in recorded history. 3.6 ks: The length of one hour (h), the time for the minute hand of a clock to cycle once around the face, approximately 1/24 of one mean solar day
Thus the first term to appear between 1 / 3 and 2 / 5 is 3 / 8 , which appears in F 8. The total number of Farey neighbour pairs in F n is 2| F n | − 3. The Stern–Brocot tree is a data structure showing how the sequence is built up from 0 ( = 0 / 1 ) and 1 ( = 1 / 1 ) , by taking successive mediants.
Thus a (not necessarily whole) number greater than or equal to 61 interpreted as a date and time are the (real) number of days after December 30, 1899, 0:00, a non-negative number less than 60 is the number of days after December 31, 1899, 0:00, and numbers with whole part 60 represent the fictional day.
Particular values of the gamma function. The gamma function is an important special function in mathematics. Its particular values can be expressed in closed form for integer and half-integer arguments, but no simple expressions are known for the values at rational points in general.
Rubidium (37 Rb) has 36 isotopes, with naturally occurring rubidium being composed of just two isotopes; 85 Rb (72.2%) and the radioactive 87 Rb (27.8%). 87 Rb has a half-life of 4.92 × 1010 years. It readily substitutes for potassium in minerals, and is therefore fairly widespread. 87 Rb has been used extensively in dating rocks; 87 Rb decays ...