موسوعة العلمـاء و المخترعين .. العلمـاء بالترتيب حسب اسم الشهرة .. الحرف ٦_د

Encyclopedia of Scientists and Inventors.. Scientists in order according to their nickname.. Letter 6_D

⏹ Diels, Otto

German organic chemist (1876 - 1954) ·
Diels worked as a chemistry teacher at Kiel University for thirty-two years, 1916-1948. His most famous work is the preparation of double ketones and the preparation of carbon dioxide C3O2. Diels is the discoverer of the chemical reaction known by his name, the Diels-Alder reaction » • (Diels Alder reaction).
(See Al-Durr and the diene interaction) This interaction is very important in the manufacture of plastics (Plastics) • Diels and his student Al-Durr together won the Nobel Prize for Chemistry in 1950.

⏹ Dillon, Pierre Louis
Dulong, Pierre Louis

French chemist (1785 - 1838)
Delon received medical training, but he worked as a professor of chemistry and then of physics in Paris.
Dillon discovered nitrogen trichloride, a highly explosive substance. During his participation with Petit in the study of refraction coefficients and the specific heat of gases, Dillon developed the law and the constancy of atomic heat. In the year 1815, Dillon indicated that acids are compounds of hydrogen that can be replaced by a metal, and this theory is close to another theory developed by Davy.
One of Dillon's achievements is the formula that bears his name and related to the calorific value of fuel.

⏹ Delisle, Joseph Nicolas
. Delisle, Joseph Nicolas

French astronomer and mathematician (1688-1768)
. Delisle excelled in both astronomy, mathematics and geography. It happened that Delisle noticed the emergence of a point of light scattering in the center of the shadow of a small circular body, but the importance of this observation was not understood at that time.
Delisle interpreted the sun's corona as arising from light refraction, and designed a method for observation
The transmission of Venus and Mercury.

⏹ Dima, Jean-Baptiste I train him
Jean Baptiste André and Dumas

French chemist (1800 - 1884)
Dima studied chemistry in Geneva, then became a professor of chemistry in Paris. Dima conducted research in organic chemistry, and was able, in cooperation with Peligot, to define methyl alcohol. He was also able to separate and anthracene from coal tar. He always differentiated between organic chemistry and inorganic chemistry. He also carried out extensive studies on the composition of water and its vapor density. He also made several determinations of the atomic weights of a number of materials. In his last days, Dima devoted himself to political work, so he occupied the position of Minister of Education.

⏹ Demoivre Abraham

English mathematician of French origin (1667 - 1754)
De Moivre's name shone as an athlete, so he was chosen as a fellow in the British Royal Society, and he was arbitrated in the dispute that arose between Isaac Newton (the English) and Gottfried Leibniz, the German (Issac Newton and Gottfried).
About who is the inventor of differential computation (Liebnetz) De Moivre's most important achievements are the theories he developed about expansions of trigonometrical functions.

⏹ De Morgan, Augustus
De Morgan, Augustus

English mathematician (1806-1871) ·
De Morgan learned in Cambridge and then worked as a professor of mathematics in London after differences because of his religion prevented him from advancing at Cambridge University • De Morgan's fame was not limited to his position as a mathematician, but he was also famous in the field of logic.
De Morgan wrote on arithmetic, algebra, and triangles, and there is a mathematical theory that still bears his name. One of De Morgan's most famous writings is his book entitled: Budget of Paradoxes.

⏹ DeHamel de Mondo, Enri Lowe
Duhamel du Monceau Henri Louis

French chemist and botanist (1700-1782)
Dehamel de Monceau trained under Jussieu in Paris and was interested in various problems related to agriculture. Dehamel de Monceau was an authority on plant nutrition and was the first to distinguish between potash and soda.

⏹ Dewar, Sir James Dewar, Sir James

Scottish chemist ( 1842 - 1923 )
Dewar studied in Freiburg and Ghent, then worked as a professor of experimental philosophy in Cambridge. He also worked as a professor of chemistry at the Royal Institution in London.
Dewar was selected as a Fellow of the Royal Society and won the Rumford Prize for his research into the properties of matter at low temperatures, especially with regard to the magnetic behavior of liquid oxygen and ozone (oxygen with three atoms). In 1868, Dewar managed to liquefy hydrogen for the first time, measured its refractive index, and managed to freeze hydrogen in 1899. Dewar invented a vessel that bears his name (Dewar flask) and used it in air-vacuuming operations. In studying phosphorescence, Dewar concluded that many familiar materials, such as eggshells and feathers, show phosphorylation. At the temperature of the liquid air, Dewar made a direct measurement of the speed of helium generation from one of the pure radium salts, and participated with Abel in the production of the explosive cordite.

⏹ Dioscorides, Pedanius
Dioscorides, Pedanius

Greek physician (born around 50 AD, date of death unknown).

Dioscorides served as a military surgeon in Nero's army. Dioscorides was one of the first to engage in botany. In his book, De Materia Medica, he described about six hundred plants that were used for treatment until the Middle Ages. Perhaps his reference to the use of mandrake (or Al-Milfaha, which is from the Solanaceae family) for its hypnotic effect for those undergoing surgeries, is the first reference to surgery under anesthesia. .

⏹ Diophantus

Alexandrian athlete (unspecified nationality from the third and fourth centuries AD).
Diophantus was the first to write about mathematics, which the Arabs called the science of algebra. Therefore, Diophantus is called the father of algebra.
Diophantus spent the clear period of his life in Alexandria. He left six books on the science of arithmetic (arithmetics), which included average equations with reasonable equivalents that required a logical solution, and called them Diophantine equations.