**Pelageia Kochina** was a Russian applied mathematician, known for her work on fluid mechanics and hydrodynamics.

- It was in Astrakhan, the city of her birth, that Pelageia began her schooling.
- Pelageia Polubarinova recovered and went on to complete her degree course, graduating with a degree in pure mathematics in 1921.
- After graduating Pelageia Polubarinova continued working at the Main Geophysical Laboratory under A A Friedmann.
- It was this work with Friedmann which turned Pelageia Polubarinova's interests towards hydrodynamics and this would be the focus of much of the work she undertook throughout her life.
- As an undergraduate he had already met Pelageia Polubarinova and the two found that they had much in common for Kochin's research was on meteorology, gas dynamics and shock waves in compressible fluids.
- Kochina gave up the teaching that she had been doing and turned her attention to full time research.
- Kochina continued her researches in the Mechanics Institute and in the following year she was awarded a Doctorate in Physical and Mathematical Science.
- Of course the year 1940 when Kochina received her doctorate was after the start of World War II.
- By 1943 the German army had suffered defeats by Soviet troops and Moscow was safe enough for Kochina to return.
- At the time of his death he had been in the middle of lecture courses and Kochina took over the courses and completed delivering them.
- On the 4 December 1946 Kochina was elected a Corresponding Member of the Division of Technical Sciences of the USSR Academy of Sciences.
- Also in 1946 Kochina was awarded the State Prize for her major contributions.
- In 1970 Kochina returned to Moscow where she became the Director in the Mathematical Methods of Mechanics Section of the USSR Academy of Sciences.
- In 1979 Kochina was awarded the Order of the Friendship of Nations, then in 1994 an international conference was held in St Petersburg on complex analysis and free boundary layer problems to celebrate her 95th birthday.
- Kochina delivered the opening address at the Conference.
- Let us now say a little about Kochina's two main areas of mathematical research, namely fluid mechanics and the history of mathematics.
- Again looking at porous media, Kochina studied the flow of fluids into oil wells and the problem of the motion of subterranean water in a medium composed of horizontal strata of ground of various permeabilities.
- As well as studying the application of mathematics to physical problems, Kochina sometimes published papers on solving mathematical problems motivated by the physics.
- In 1991 a volume of selected works by Kochina on hydrodynamics and filtration theory was published.
- Finally we must look at the important contribution Kochina has made to the history of mathematics.
- The first point that we should make here is that Kochina's publications were the result of research undertaken practically throughout her whole life.
- When one considers that Kochina was 86 years old when this brilliant scholarly book was published, one can only marvel.
- But, as if this achievement was not enough for someone of her age, Kochina published another major biography two years later: Gosta Mittag-Leffler 1846-1927.
- In 1988 Kochina published a 624 page book on her reminiscences and works.
- Further works were to appear by Kochina.
- In 1999, when Kochina was 100 years old, she published Some properties of a fractional-linear transformation written jointly with N N Kochina.

Born 13 May 1899, Astrakhan, Russia. Died 3 July 1999, Moscow, Russia.

View full biography at MacTutor

Origin Russia, Women

**Oâ€™Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive