Articles with WorldCat Entities identifiers

Oskar Perron (7 May 1880 – 22 February 1975) was a German mathematician.
He was a professor at the University of Heidelberg from 1914 to 1922 and at the University of Munich from 1922 to 1951. He made numerous contributions to differential equations and partial differential equations, including the Perron method to solve the Dirichlet problem for elliptic partial differential equations. He wrote an encyclopedic book on continued fractions Die Lehre von den Kettenbrüchen. He introduced Perron's paradox to illustrate the danger of assuming that the solution of an optimization problem exists:

Let N be the largest positive integer. If N > 1, then N2 > N, contradicting the definition of N. Hence N = 1.

Charles François Antoine Morren (3 March 1807 in Ghent – 17 December 1858 in Liège), was a Belgian botanist and horticulturist, and Director of the Jardin botanique de l’Université de Liège.Morren taught physics at Ghent University between 1831 and 1835. At the same time he studied medicine and graduated in 1835. He became Professor extraordinarius of botany at the University of Liège from 1835 to 1837, and full professor from 1837 to 1854.
Pollination of Vanilla orchids is required to make the plants produce the pods from which vanilla extract is obtained. In 1837, Morren was among the first to publish a method for artificial pollination of Vanilla, but his method proved financially unworkable and was not deployed commercially. In 1841, Edmond Albius, a 12-year-old slave who lived on the French island of Réunion in the Indian Ocean, discovered that the plant could be hand-pollinated. Hand-pollination allowed global cultivation of the plant. Noted French botanist and plant collector Jean Michel Claude Richard falsely claimed to have discovered the technique three or four years earlier, but by the end of the 20th century, Albius was considered the true discoverer.
He was the father of Charles Jacques Édouard Morren. Morren and his son produced the journal La Belgique Horticole (35 volumes, 1851–1885).
Morren also coined the term phenology, which refers to the scientific discipline that studies the seasonal cycles of animals and plants. Morren first used the term phenology in 1849 during a public lecture at the Academy of Brussels. The first use of the term phenology in a scientific paper dates back to 1853 when Morren published “Souvenirs phénologiques de l’hiver 1852-1853” (“Phenological memories of the winter 1852-1853”). This paper describes an exceptionally warm winter when plants exhibited unusually phenological patterns.

This botanist is denoted by the author abbreviation C.Morren when citing a botanical name.

Gustaaf Adolf Frederik Molengraaff (27 February 1860 – 26 March 1942) was a Dutch geologist, biologist and explorer. He became an authority on the geology of South Africa and the Dutch East Indies.
Gustaaf Molengraaff studied mathematics and physics at Leiden University. From 1882 he studied at Utrecht University. As a student he made his first journey overseas when he joined the 1884–1885 expedition to the Dutch Antilles led by Willem Frederik Reinier Suringar and Karl Martin. He became PhD with a thesis on the geology of Sint Eustatius. He studied crystallography in Munich, where he also took the opportunity to study the geology of the Alps nearby.
In 1888 Molengraaff took a job as a teacher at the University of Amsterdam. Before his assignment courses in geology were given by the chemist Jacobus Henricus van 't Hoff. During his assignment in Amsterdam, Molengraaff travelled to South Africa to study gold deposits (1891) and to Borneo (1894) where he explored large parts of the inland. Teaching at Amsterdam was not to his liking, because there were too little materials and students available.
In 1897 Molengraaff became "state geologist" of the Transvaal Republic. His task was to start the geological survey of the Transvaal. While mapping the Transvaal he discovered the Bushveld complex. In 1900 he got involved in the Second Boer War and had to return to the Netherlands. This gave him time to write a report on the geology of the Transvaal, and travel to Celebes, where he (again) studied gold deposits.
Due to his reputation as a geologist he could return to South Africa in 1901 to work as a geological consultant. One of his assignments was to describe the newly found Cullinan diamond for the Central Bank of South Africa. Meanwhile the Boer War still had his attention. One of his ideas was to give each soldier a small tin identity card, which later became practice in armies around the world.
In 1906 he became professor at Delft University and this time he got enough resources and students to make his work successful. The same year he became member of the Royal Netherlands Academy of Arts and Sciences. In 1910-1911 he led a geological expedition to Timor. His research at Delft was mainly on the material collected during that expedition, and on the geology of the Netherlands. In 1922 he was a guide, along with A L Hall, of the Shaler Memorial Expedition to South Africa, organized by Harvard University. On the expedition he met Alexander Du Toit, both geologists were among the (at that time rare) supporters of Alfred Wegeners' continental drift theory.
Molengraaff was a close friend of W. F. Gisolf, who named his youngest son after him but died in a Japanese concentration camp.
Molengraaff retired in 1930.

Maurice Lévy (February 28, 1838, in Ribeauvillé – September 30, 1910, in Paris) was a French engineer and member of the Institut de France.
Lévy was born in Ribeauvillé in Alsace. Educated at the École Polytechnique, where he was a student of Adhémar Jean Claude Barré de Saint-Venant, and the École des Ponts et Chaussées, he became an engineer in 1863. During the Franco-Prussian War (1870–1871), he was entrusted by the Government of National Defense with the control of part of the artillery. During the next decade he held several educational positions, becoming professor at the École Centrale in 1875, member of the commission of the geodetic survey of France in 1879, and professor at the Collège de France in 1885.

Friedrich Hermann Leuchs (8 August 1879 – 2 May 1945) was a German chemist.

Constantin Marie Le Paige (9 March 1852 – 26 January 1929) was a Belgian mathematician.
Born in Liège, Belgium, Le Paige began studying mathematics in 1869 at the University of Liège. After studying analysis under Professor Eugène Charles Catalan, Le Paige became a professor at the Université de Liège in 1882.
While interested in astronomy and the history of mathematics, Le Paige mainly worked on the theory of algebraic form, especially algebraic curves and surfaces and more particularly for his work on the construction of cubic surfaces. Le Paige remained at the university until his retirement in 1922.

Thomas Murray MacRobert (4 April 1884, in Dreghorn, Ayrshire – 1 November 1962, in Glasgow) was a Scottish mathematician. He became professor of mathematics at the University of Glasgow and introduced the MacRobert E function, a generalisation of the generalised hypergeometric series.

Ernest Jean Philippe Fauque de Jonquières (born Carpentras, France 3 July 1820; died Mousans-Sartoux, France 12 August 1901) was a French mathematician and naval officer who made several contributions in geometry.
Jonquières attended the naval school at Brest, and later joined the French Navy. in 1841 he became a lieutenant, and from 1849 to 1850 he served on the staff of the Admiral in Paris. During this time, Jonquières became a close associate of Michel Chasles, whose works he had studied. During his subsequent time at sea, he continued his mathematical studies, and won a part of the Grand Prix of the French Academy of Sciences in 1862.
In 1865, Jonquières became a captain and was sent to Saigon to organize a French agricultural and industrial exhibition. He played an important role in the development of current Vietnam as a French colony. Later, he was head of the local naval depot and its maps and plans. In 1874, Jonquières was made Vice-Admiral. He retired in 1885.

Charles Jacob (1878-1962) was a French geologist. He served as the president of the French National Centre for Scientific Research from 1940 to 1944 under Vichy France.

Noël Armand Fiessinger (24 December 1881 – 15 January 1946) was a French physician.