Pierre and Marie Curie, circa 1890s. Marie Skłodowska-Curie conducted pioneering research on radiation, and was the first woman to be awarded a Nobel Prize, and the only person to be awarded two Nobel Prizes in multiple fields (Physics, 1903, Chemistry, 1911).
A Leidenfrost droplet impregnated with hydrophilic beads hovers on a thin film of its own vapor. The Leidenfrost effect occurs when a liquid touches a solid surface much, much hotter than its boiling point. Instead of boiling entirely away, part of the liquid vaporizes and the remaining liquid survives for extended periods while the vapor layer insulates it from the hot surface. Hydrophilic beads inserted into Leidenfrost water droplets initially sink and are completely enveloped by the liquid. But, as the drop evaporates, the beads self-organize, forming a monolayer that coats the surface of the drop. The outer surface of the beads drys out, trapping the beads and causing the evaporation rate to slow because less liquid is exposed. (Photo credit: L. Maquet et al.; research paper - pdf)
Irène Curie-Joliot (1897 – 1956)
Irène Curie, born in Paris, September 12, 1897, was the daughter of Pierre and Marie Curie, and since 1926 the wife of Frédéric Joliot. After having started her studies at the Faculty of Science in Paris, she served as a nurse radiographer during the First World War. She became Doctor of Science in 1925, having prepared a thesis on the alpha rays of polonium.
Either alone or in collaboration with her husband, she did important work on natural and artificial radioactivity, transmutation of elements, and nuclear physics; she shared the Nobel Prize in Chemistry for 1935 with him, in recognition of their synthesis of new radioactive elements, which work has been summarized in their joint paperProduction artificielle d’éléments radioactifs. Preuve chimique de la transmutation des éléments (1934). Marie and Irène was the first parent-child couple to have independently won Nobels.
In 1938 her research on the action of neutrons on the heavy elements, was an important step in the discovery of uranium fission. Appointed lecturer in 1932, she became Professor in the Faculty of Science in Paris in 1937, and afterwards Director of the Radium Institute in 1946. Being a Commissioner for Atomic Energy for six years, Irène took part in its creation and in the construction of the first French atomic pile (1948). She was concerned in the inauguration of the large centre for nuclear physics at Orsay for which she worked out the plans. This centre was equipped with a synchro-cyclotron of 160 MeV, and its construction was continued after her death by F. Joliot.
She took a keen interest in the social and intellectual advancement of women; she was a member of the Comité National de l’Union des Femmes Françaises and of the World Peace Council. In 1936 Irène Joliot-Curie was appointed Undersecretary of State for Scientific Research. She was a member of several foreign academies and of numerous scientific societies, had honorary doctor’s degrees of several universities, and was an Officer of the Legion of Honour. All those years working with radioactivity took a toll, however, and Irène died of leukemia in 1956. [x]
In 1947, Dr. Marie Daly became the first African-American woman to earn a Ph.D. in Chemistry when she graduated from Columbia University. A trailblazer in the field of biochemistry, Dr. Daly researched the connection between high cholesterol and heart disease. #WomenInSTEM (Photo courtesy of Albert Einstein College of Medicine, D. Samuel Gottesman Library Archives)
The BZ reaction can produce three-dimensional patterns in test tubes from an initially homogeneous solution. The most common pattern, a scroll wave, is shown above. Some scrolls evolve further in to spherelike structures (Arthur E. Burgess, Glasgow College of Technology).
During experiments designed to model catalysis in the Krebs cycle, B.P. Belousov saw that his mixture of citric acid, acidified bromate (BrO3–), and a ceric salt periodically turned from yellow to colorless and back to yellow. Belousov’s 1951 manuscript was rejected, even though it contained a simple recipe for producing the oscillations, by an editor who wrote that such a phenomenon was quite impossible! His work was not published until seven years later in an obscure symposium proceedings.
Fortunately, Belousov’s discovery was taken up by another Russian biophysicist, A.M. Zhabotinskii, then a graduate student in biochemistry at Moscow State University. Zhabotinskii developed the reaction further by replacing the citric acid with malonic acid and published several papers on the phenomenology and mechanism of what is now known as the Belousov-Zhabotinskii (BZ) reaction. One of Zhabotinskii’s findings was that under appropriate conditions an initially homogeneous layer of BZ reagent left unstirred could develop a beautiful and complex pattern of concentric rings whose color and composition differed from that of the bulk of the medium. The reaction could oscillate in space as well as in time.
The BZ reaction made an excellent lecture demonstration, but it remained outside the scientific mainstream until the early 1970s. Then, Richard M. Noyes and Richard J. Field at the University of Oregon, together with Endre Koros, a visitor from Eotvos University in Budapest, made a crucial suggestion. They proposed a detailed mechanism for the BZ reaction consisting of a series of elementary steps. They showed qualitatively how such a model could result in the observed oscillations and presented stoichiometric and thermodynamic arguments in support of the reactions chosen.
Shortly thereafter, Noyes and Field collaborated with David Edelson of Bell Laboratories on a computer simulation in which the 18 rate equations of the Field-Koros-Noyes (FKN) scheme were numerically integrated. The resulting plots of concentration vs. time were indeed oscillatory. This work showed that chemical oscillation is generated by and consistent with the same physicochemical principles followed by all other chemical reactions.
-Irving R. Epstein
Patterns in Time and Space—Generated by Chemistry
Basic explanation of where sine and cosine are derived from.
As the circle is drawn the y axis corresponds to a sine wave, while the blue wave corresponds to a cosine wave.
This phenomenon can be seen in many places across the universe. Notably, in the electromagnetic behaviour of a light wave.