paragraph_text: The X-ray crystal density method is primarily a method for determining the Avogadro constant NA but as the Avogadro constant is related to the Planck constant it also determines a value for h. The principle behind the method is to determine NA as the ratio between the volume of the unit cell of a crystal, measured by X-ray crystallography, and the molar volume of the substance. Crystals of silicon are used, as they are available in high quality and purity by the technology developed for the semiconductor industry. The unit cell volume is calculated from the spacing between two crystal planes referred to as d220. The molar volume Vm(Si) requires a knowledge of the density of the crystal and the atomic weight of the silicon used. The Planck constant is given by

paragraph_text: The International Who's Who in Music is a biographical dictionary and directory originally published by the International Biographical Centre located in Cambridge, England. It contains only biographies of persons living at the time of publication and includes composers, performers, writers, and some music librarians. The biographies included are solicited from the subjects themselves and generally include date and place of birth, contact information as well as biographical background and achievements.

paragraph_text: Crystal Palace Ward is an electoral ward in the London Borough of Bromley, covering part of the Crystal Palace area and the entirety of Crystal Palace Park. It has an estimated population of 12,432 and is represented on the council by two councillors - Angela Wilkins and Richard Williams - both of which are affiliated to the Labour Party.

paragraph_text: Fluid and crystallized intelligence were originally identified by Raymond Cattell. Concepts of fluid and crystallized intelligence were further developed by Cattell's student, John L. Horn. Since Cattell's and Horn's publications, the concepts of fluid and crystallized intelligence have become so ingrained in the field of intelligence that they are no longer routinely attributed to Cattell or Horn -- much as Cattell's scree plot became ingrained in the practice of factor analysis or Freud's concept of the subconscious is ingrained in psychology and in the public's perceptions of the mind.

paragraph_text: Crystal Sound () is a sound in Antarctica between the southern part of the Biscoe Islands and the coast of Graham Land, with northern limit Cape Evensen to Cape Leblond and southern limit Holdfast Point, Roux Island, Liard Island and the Sillard Islands. It was so named by the UK Antarctic Place-Names Committee in 1960 because many features in the sound are named for men who have undertaken research on the structure of ice crystals.

paragraph_text: The Matsuyama Rocks () are a small group of rocks close off the west side of Stefan Ice Piedmont, Graham Land, Antarctica. They are located towards the western end of Crystal Sound. They were mapped from air photos taken by the Falkland Islands and Dependencies Aerial Survey Expedition (1956–57), and were named by the UK Antarctic Place-Names Committee after Motonori Matsuyama, Professor of Geology and Geophysics at Kyoto University, Japan, who made laboratory studies of the crystal forms of ice.

paragraph_text: Pittsburgh is an album by American jazz pianist Ahmad Jamal featuring performances recorded in 1989 and released on the Atlantic label.

paragraph_text: Petrologists can also use fluid inclusion data and perform high temperature and pressure physical experiments to understand the temperatures and pressures at which different mineral phases appear, and how they change through igneous and metamorphic processes. This research can be extrapolated to the field to understand metamorphic processes and the conditions of crystallization of igneous rocks. This work can also help to explain processes that occur within the Earth, such as subduction and magma chamber evolution.

paragraph_text: Alpine crystals have been studied and collected for hundreds of years, and began to be classified in the 18th century. Leonhard Euler studied the shapes of crystals, and by the 19th century crystal hunting was common in Alpine regions. David Friedrich Wiser amassed a collection of 8000 crystals that he studied and documented. In the 20th century Robert Parker wrote a well-known work about the rock crystals of the Swiss Alps; at the same period a commission was established to control and standardize the naming of Alpine minerals.

paragraph_text: The end of World War II brought a baby boom to many countries, especially Western ones. There is some disagreement as to the precise beginning and ending dates of the post-war baby boom, but it is most often agreed to have begun in the years immediately after the war, though some place it earlier at the increase of births in 1941 - 1943. The boom started to decline as birth rates in the United States started to decline in 1958, though the boom would only grind to a halt 3 years later in 1961, 20 years after it began.

paragraph_text: Creed of Gold is a 2014 film about fictional corruption at the Federal Reserve. It was produced by Crystal Creek Media and directed by Daniel Knudsen. Filming of "Creed of Gold" took place in several locations near Indianapolis, Indiana and Detroit, Michigan with some additional photography taking place on location in New York City.

paragraph_text: Crystal Springs is an unincorporated community in Kidder County, North Dakota, United States. Crystal Springs is located along Interstate 94 east of Tappen.

paragraph_text: Crystal is an album by American jazz pianist Ahmad Jamal featuring performances recorded in 1987 and released on the Atlantic label.

paragraph_text: Crystal Bay is a neighborhood of Orono, Hennepin County, Minnesota, United States. Crystal Bay has its own post office with ZIP code 55323.

paragraph_text: The Nakaya Islands are a small group of islands in Crystal Sound, about 18 km northeast of Cape Rey, Graham Land in Antarctica. They were named by United Kingdom Antarctic Place-Names Committee (UK-APC) after Ukichiro Nakaya (1900–62), a Japanese Professor of Physics from the University of Hokkaido, who specialized in the field of investigating the structure of ice crystals and snowflakes.

paragraph_text: As an alternative to string theory, Kleinert used the complete analogy between non-Euclidean geometry and the geometry of crystals with defects to construct a model of the universe called the World Crystal or Planck-Kleinert crystal.  In this model, matter creates defects in spacetime which generate curvature. This curvature reproduces all the effects of general relativity, but leads to different physics than string theory at the scale of the Planck length. This theory inspired Italian artist Laura Pesce to create glass sculptures entitled "world crystal" (see also lower left on this page).

paragraph_text: Under standard conditions, germanium is a brittle, silvery-white, semi-metallic element. This form constitutes an allotrope known as α-germanium, which has a metallic luster and a diamond cubic crystal structure, the same as diamond. While in crystal form, germanium has a displacement threshold energy of

paragraph_text: The Geode Nunataks () are a group of small nunataks on the west side of Sibelius Glacier, immediately north of the northern extremity of the Finlandia Foothills, in northeast Alexander Island, Antarctica. They were so named by the UK Antarctic Place-Names Committee in 1977; the nunataks are composed of lava flows with abundant geodes (cavities within the rock containing quartz and calcite crystals).

paragraph_text: The Crystal Springs Fountain is a historic roadside fountain along old U.S. Route 10 near Crystal Springs, North Dakota. It was listed on the National Register of Historic Places in 2010. It provided spring water and was a rest stop for travelers.

paragraph_text: In psychology, fluid and crystallized intelligence (respectively abbreviated Gf and Gc) are factors of general intelligence, originally identified by Raymond Cattell. Concepts of fluid and crystallized intelligence were further developed by Cattell's student John L. Horn.

Question: Where was the performer of Crystal born?
Answer: Pittsburgh