Wrocław

Wrocław (/ˈvrɒtswəf/; Polish pronunciation: [ˈvrɔt͡swaf], German: Breslau, [bʁɛs̬laʊ]; Latin: Vratislavia) is the largest city in western Poland. It is on the River Oder in the Silesian Lowlands of Central Europe, roughly 350 kilometres (220 mi) from the Baltic Sea to the north and 40 kilometres (25 mi) from the Sudeten Mountains to the south. Wrocław is the historical capital of Silesia and Lower Silesia. Today, it is the capital of the Lower Silesian Voivodeship. At various times in history, it has been part of the Kingdom of Poland, Bohemia, Hungary, the Austrian Empire, Prussia, and Germany. It became part of Poland in 1945, as a result of the border changes after the Second World War. The population of Wrocław in 2014 was 634,487, making it the fourth-largest city in Poland.

Wrocław classified as a global city by GaWC, with the ranking of high sufficiency and living standard. It was among 230 cities in the world in the ranking of the consulting company Mercer - "Best City to Live" in 2015 and the only Polish city in this ranking has been recognized as a city growing at the business center.

Mass fraction (chemistry)

In chemistry, the mass fraction is the ratio of one substance with mass to the mass of the total mixture , defined as

The sum of all the mass fractions is equal to 1:

Mass fraction can also be expressed, with a denominator of 100, as percentage by mass (frequently, though erroneously, called percentage by weight, abbreviated wt%). It is one way of expressing the composition of a mixture in a dimensionless size; mole fraction (percentage by moles, mol%) and volume fraction (percentage by volume, vol%) are others.

For elemental analysis, mass fraction (or "mass percent composition") can also refer to the ratio of the mass of one element to the total mass of a compound. It can be calculated for any compound using its empirical formula or its chemical formula

Terminology

"Percent concentration" does not refer to this quantity. This improper name persists, especially in elementary textbooks. In biology, the unit "%" is sometimes (incorrectly) used to denote mass concentration, also called "mass/volume percentage." A solution with 1 g of solute dissolved in a final volume of 100 mL of solution would be labeled as "1 %" or "1 % m/v" (mass/volume). This is incorrect because the unit "%" can only be used for dimensionless quantities. Instead, the concentration should simply be given in units of g/mL. "Percent solution" or "percentage solution" are thus terms best reserved for "mass percent solutions" (m/m = m% = mass solute/mass total solution after mixing), or "volume percent solutions" (v/v = v% = volume solute per volume of total solution after mixing). The very ambiguous terms "percent solution" and "percentage solutions" with no other qualifiers continue to occasionally be encountered.

WW

WW may refer to:

In entertainment:

W&W

W&W is a Dutch trance and electro house duo from Haarlem/Breda, consisting of Dutch Willem van Hanegem (born 25 June 1987) (Dutch pronunciation: [ˈʋɪ.ləm vɑn ˈɦaː.nə.ˌɣɛm]) and Wardt van der Harst (born 26 December 1988) [ˈʋɑrt fɑn dɛr ˈɦɑrst]. Willem is the son of the Dutch football player Willem van Hanegem.

Discography

Studio albums

Compilation albums

Singles

Other tracks

W.W. (automobile)

W.W. (Winter), was an early British car made by Winter and Company of Wandsworth, London. They made two models between 1913 and 1914.

The first car, the W.W. of 1913 was a light car powered by an 8hp V-twin engine bought in from the Precision company. This drove the rear wheels through a gear box by Chater-Lea and shaft drive to a worm gear final drive on the rear axle.

For 1914 production changed to a cyclecar. This was sold as a Winter and had a Blumfield engine and friction drive with belt to the rear axle.

The number made is not known.

See also

References