موسوعة العلمـاء و المخترعين .. العلمـاء بالترتيب حسب اسم الشهرة .. الحرف ٢_د

Encyclopedia of Scientists and Inventors.. Scientists in order according to their nickname.. Letter 2_D

Dunning, John Ray

American physicist (1907 - )
Denning studied at the University of Nebraska and Columbia and worked in the latter as a professor of physics - Denning participated with Nier, Booth and Grosse in reaching practical proof of uranium-235 fission by slow neutrons. This result paved the way for the production of the atomic bomb.

⏹ Dunning, William Frederick
William Frederick Denning,

English astronomer (1848 - 1931)
Denning was known as an amateur astronomer, then became a Fellow of the Astronomical Society. Denning's fame goes back to his discovery of five comets and some nebulae.
He studied a group of planets, as well as meteorites and meteors, and discovered the connection between some of the showers (sprinkles) of these moving bodies to Earth and comets. Dunning discovered a new star in the constellation Cygnus on August 20, 1920.
Dunning measured and calculated the heights and velocities of meteorites and meteors, which benefited later scientists like Cherwell from 1886 to 1957 to reach important conclusions related to the nature of the atmosphere.

⏹ Doppler, Christian Bohan
Doppler, Christian Johann

Austrian mathematician and physicist (1803-1853)
Doppler became prominent through his work in teaching mathematics in the Czech capital, Prague, then he went to «Vienna» - the capital of the Austrian Empire - to work in teaching experimental physics • He discovered the principle (or rule) that bears his name: «Doppler rule, and related to the agglutination or divergence of outgoing waves About a moving object in the case of approaching or moving away from the observer, in relation to light waves · The term "Doppler's shift" is used on the result of this phenomenon in the spectrum of distant objects, and Fizeau used these Doppler results in the study of stars. The Doppler rule finds applications in acoustic studies, in addition to its use in measuring the absolute velocity of celestial bodies and galaxies.

⏹ Dorn, Friedrich Ernst
Dorn, Friedrich Ernst

German chemist (1848 - 1916)
Dorn was educated in Kenigsberg and then taught physics in Darmstadt and Halle. Dorn discovered in 1900 that emissions of radium he called "niton" for some time and then called "radon" or radium emissions.

⏹ Douglas Andrew Ellicott
Douglass, Andrew Ellicott

American astronomer (1867 - 1962)
Douglas studied in Connecticut, then worked as an assistant at Lowell at the Flagstaff Observatory, taught physics and astronomy at the University of Arizona, and worked as director of the Steward Observatory. sunspots that are longer than the period he could count them.

⏹ Du Fay, Charles-François de Systray
Du Fay, Charles Francois de Cister ay

French chemist (1698 - 1739) ·
Du Fay worked as a chief supervisor of the gardens of the King of France, and worked in solving a number of physical and chemical problems, so he discovered the two types of electricity, which are positive and negative, as well as the relationship of attraction and repulsion between two different or similar types. Du Fay also studied the property of phosphorescence and double refraction (double refraction) of light in some solid bodies, with the exception of those that crystallize according to the cubic system.

⏹ du Vigneaud, Vincent

American biochemist (of French origin) (1910).
De Vino graduated from the University of Illinois, then worked in famous laboratories and hospitals
Then he taught biochemistry at Cornell University, and his name became famous as a result of several important achievements made by De Vino, such as the synthesis of penicillin and oxytocin, and the discovery of the composition of the vitamin called biotin.
He was awarded the Nobel Prize for Chemistry for his work and progress in the synthesis of pituitary hormones that are indispensable to the nerve centers regulating physiological behavior. Including hormones that prevent arthritis.

⏹ Domag, Gerhard Domagk, Gerhard

German biochemist (1895-1964).
Following his studies in Greifswald and Minster, Doumack became the director of the Eberfeld Institute. He discovered prontosil for research, which is a red-orange dye that contains the currently important therapeutic substance, sulfanilamide.
Which was patented by Mietzch and Klaren.
He was awarded the Nobel Prize for Physiology and Medicine in 1939, but he refused it at the request of his government during the Nazi period.