blue john also known as derbyshire spar is a semi-precious mineral, a form of fluorite with bands of a purple-blue or yellowish colour. in the uk it is found only at blue john cavern and treak cliff cavern at castleton in derbyshire. during the 19th century, it was mined for its ornamental value,.
landfills in the united kingdom were historically the most commonly used option for waste disposal. up until the 1980s, policies of successive governments had endorsed the 'dilute and disperse' approach. britain has since adopted the appropriate european legislation and landfill sites are generally operated as full containment facilities.
point in polygon algorithms: tests whether a given point lies within a given polygon; point set registration algorithms: finds the transformation between two point sets to optimally align them. rotating calipers: determine all antipodal pairs of points and vertices on a convex polygon or convex hull.
birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. these optically anisotropic materials are said to be birefringent or birefractive .the birefringence is often quantified as the maximum difference between refractive indices exhibited by the material.
this list includes those recognised minerals beginning with the letter s.the international mineralogical association is the international group that recognises new minerals and new mineral names, however minerals discovered before 1959 did not go through the official naming procedure, although some minerals published previously have been either confirmed or discredited since that date.
maschinenfabrik liezen und gießerei gesmbh is a foundry and mechanical engineering company based in liezen, austria.the company's origins date to 1939 when a factory was established in liezen for war materials production.
in thimining sorting industry, it is also called sensor-based sorting technology. optical color sorters ccd color camera combine x-ray sorting technology and nir near infrared spectrometry to pick out the impurities of ore, minerals, stone and sand products, or separate ore into two or more categories. n this article's tone or style may .
a spiral separator may process a couple tons per hour of ore, per flight, and multiple flights may be stacked in the same space as one, to improve capacity. dry spiral separators. dry spiral separators, capable of distinguishing round particles from nonrounds, are used to sort the feed by shape.
bright-field microscopy is the simplest of a range of techniques used for illumination of samples in light microscopes, and its simplicity makes it a popular technique. the typical appearance of a bright-field microscopy image is a dark sample on a bright background, hence the name.
a standard order is often called ascending corresponding to the fact that the standard order of numbers is ascending, i.e. a to z, 0 to 9 , the reverse order descending z to a, 9 to 0 . for dates and times, ascending means that earlier values precede later ones e.g. 1/1/2000 will sort ahead of 1/1/2001. common sorting algorithms
history early history. the museum was founded in 1716 in saint petersburg as a mineral cabinet of kunstkamera.as a base for this mineral cabinet a collection of 1195 specimens was bought by gotvald, a doctor of medicine from danzig, at the behest of tsar peter the great.this collection was enriched by the material from russian deposits and opened for public view in 1719.
blue john also known as derbyshire spar is a semi-precious mineral, a form of fluorite with bands of a purple-blue or yellowish colour. in the uk it is found only at blue john cavern and treak cliff cavern at castleton in derbyshire.during the 19th century, it was mined for its ornamental value, and mining continues on a small scale. deposits of fluorite have been recently found in china .