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Stefan Procopiu

Stefan Procopiu

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Ștefan Procopiu was a Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

n physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

.

Biography


Procopiu was born in 1890 in Bârlad
Bârlad
Bârlad is a city in Vaslui County, Romania. It lies on the banks of the Bârlad River, which waters the high plains of eastern Moldavia....

, Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

. His father, Emanoil Procopiu, was employed at the Bârlad courthouse. His mother, Ecaterina Tașcă was the daughter of Gheorghe I. Tașcă (see Tașcă family)
He attended the Gheorghe Roșca Codreanu High School
Gheorghe Rosca Codreanu High School
The Gheorghe Roşca Codreanu National College is a high school in the city of Bârlad, Romania.The school was established by Gheorghe Roşca Codreanu as a gymnasium in 1858, being upgraded to a complete high school in 1864. It is the fourth high school established in Romania, after ones in Bucharest,...

 in Bârlad from 1901 to 1908, continuing his studies at the Faculty of Sciences of the "Alexandru Ioan" Cuza University of Iași from 1908 to 1912. After graduation he became assistant to professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...

 Dragomir Hurmuzescu.

In 1919 he obtained a scholarship
Scholarship
A scholarship is an award of financial aid for a student to further education. Scholarships are awarded on various criteria usually reflecting the values and purposes of the donor or founder of the award.-Types:...

 to continue his studies in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

, attending courses of famous scientists, such as Gabriel Lippmann
Gabriel Lippmann
Jonas Ferdinand Gabriel Lippmann was a Franco-Luxembourgish physicist and inventor, and Nobel laureate in physics for his method of reproducing colours photographically based on the phenomenon of interference....

, Marie Curie
Marie Curie
Marie Skłodowska-Curie was a physicist and chemist famous for her pioneering research on radioactivity. She was the first person honored with two Nobel Prizes—in physics and chemistry...

, Paul Langevin
Paul Langevin
Paul Langevin was a prominent French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the Comité de vigilance des intellectuels antifascistes, an antifascist organization created in the wake of the 6 February 1934 far right riots...

, Aimé Cotton
Aimé Cotton
Aimé Auguste Cotton was a French physicist known for his studies of the interaction of light with chiral molecules...

. On 5 March 1924, Procopiu obtained the title of doctor in physics
Doctorate
A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder to teach in a specific field, A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder...

 with the thesis "On the electric birefringence of suspensions" presented to a commission including professor Aimé Cotton
Aimé Cotton
Aimé Auguste Cotton was a French physicist known for his studies of the interaction of light with chiral molecules...

 as coordinator and Charles Fabry
Charles Fabry
Maurice Paul Auguste Charles Fabry FMRS was a French physicist.-Life:Fabry graduated from the Ecole Polytechnique in Paris and received his doctorate from the University of Paris in 1892, for his work on interference fringes, which established him as an authority in the field of optics and...

 and Henri Mouton
Henri Mouton
Henri Mouton [5 September 1869, Cambrai - 13 June 1935, Bezons ] was a French scientist.He entered the École normale supérieure in 1889. He was a biologist at the Institut Pasteur, then...

 as cross-examiners.

After his return to Romania on January 15, 1925 professor of the gravitation
Gravitation
Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...

, heat
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...

 and electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

 department of the "Alexandru Ioan Cuza" University of Iași, replacing his former teacher Dragomir Hurmuzescu, who had retired., Procopiu coordinated the department until his retirement in 1962. At the same time he was appointed professor at the "Gheorghe Asachi" Polytechnic Institute of Iași
Gheorghe Asachi Technical University of Iasi
The Gheorghe Asachi Technical University is a public university located in Iaşi, Romania. It has the oldest tradition in Romania in engineering education and is second ranked among the technical institutions of higher education, and the fifth among all universities in Romania, in the national...


In 1939 Ștefan Procopiu published his treatise
Treatise
A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject.-Noteworthy treatises:...

 on "Electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

 and Magnetism
Magnetism
Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...

", followed in 1948 by his monography on “Thermodynamics
Thermodynamics
Thermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...

”.

On June, 1948 he was appointed corresponding member of the Romanian Academy
Romanian Academy
The Romanian Academy is a cultural forum founded in Bucharest, Romania, in 1866. It covers the scientific, artistic and literary domains. The academy has 181 acting members who are elected for life....

, being promoted to full membership on July 2, 1955. In 1964 he was awarded the Romanian State Prize. He was also decorated with the Order of Work (Ordinul Muncii), Order of the Star of Romania
Order of the Star of Romania
The Order of the Star of Romania is Romania's highest civil order. It is awarded by the President of Romania...

 and the Order of Scientific Merit.
Procopiu was also selected twice as member in the Commission for the award of the Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...

.

Procopiu was also deeply involved in the cultural life of the city of Iași. He was an active member of the Board of Directors
Board of directors
A board of directors is a body of elected or appointed members who jointly oversee the activities of a company or organization. Other names include board of governors, board of managers, board of regents, board of trustees, and board of visitors...

 of the National Theatre “Vasile Alecsandri” of Iași.

Ștefan Procopiu died on August 22, 1972 in Iași
Iasi
Iași is the second most populous city and a municipality in Romania. Located in the historical Moldavia region, Iași has traditionally been one of the leading centres of Romanian social, cultural, academic and artistic life...

, Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

, at the age of 82.

Scientific activity


Ștefan Procopiu started scientific research even before graduating. He continued this activity while he was assistant professor.

The magnetic moment of the electron


The first important paper by Ștefan Procopiu is "Determining the Molecular Magnetic Moment by M. Planck’s Quantum Theory". After studying Planck’s quantum theory and Langevin’s magnetism theory, established the magnetic moment
Magnetic moment
The magnetic moment of a magnet is a quantity that determines the force that the magnet can exert on electric currents and the torque that a magnetic field will exert on it...

 of the electron and determined the physical constant
Physical constant
A physical constant is a physical quantity that is generally believed to be both universal in nature and constant in time. It can be contrasted with a mathematical constant, which is a fixed numerical value but does not directly involve any physical measurement.There are many physical constants in...

 of magnetic moment
Magnetic moment
The magnetic moment of a magnet is a quantity that determines the force that the magnet can exert on electric currents and the torque that a magnetic field will exert on it...

, named magneton
Magneton
Magneton may refer to:* Bohr magneton, a physical constant of magnetic moment named after Niels Bohr* Nuclear magneton, a physical constant of magnetic moment* Parson magneton, a hypothetical object in atomic physics suggested by Alfred Lauck Parson in 1915...

. Ștefan Procopiu published his results two years before Niels Bohr
Niels Bohr
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in...

 made the same discovery independently. The magneton is now known as Bohr–Procopiu magneton.

Continuing his studies, in 1954 he established a method for the experimental determination of the magneton, which he improved in 1963.

Other research before and during World War I


Ștefan Procopiu also worked on wireless communications and in 1913 published a paper on “Experimental Research on Wireless Telegraphy”. In 1916 he invented a device for locating and establishing the depth of bullets in the bodies of the wounded soldiers.

Longitudinal depolarization of light


In 1921, Procopiu discovered and analyzed in the Physics Laboratory of Sorbonne University
University of Paris
The University of Paris was a university located in Paris, France and one of the earliest to be established in Europe. It was founded in the mid 12th century, and officially recognized as a university probably between 1160 and 1250...

 a new optical phenomenon which consisted in the longitudinal depolarization of light by suspensions and colloids. In 1930, the occurrence was designated as "Procopiu Phenomenon" by prof. Augustin Boutaric. Part of this research was included in Procopiu's doctoral thesis.

Electromotive force of galvanic elements


Thus, in 1930, studying the Barkhausen effect
Barkhausen effect
The Barkhausen effect is a name given to the noise in the magnetic output of a ferromagnet when the magnetizing force applied to it is changed...

, Ștefan Procopiu discovered a circular effect of magnetic discontinuity. In 1951, this effect was named "Procopiu Effect". This discovery had important applications in the development of the memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....

 of computers.

Studies of the Earth's magnetic field


Earth’s magnetism was a continuous concern of Ștefan Procopiu, For 25 years he studied this phenomenon
Phenomenon
A phenomenon , plural phenomena, is any observable occurrence. Phenomena are often, but not always, understood as 'appearances' or 'experiences'...

 in Romania and developed the magnetic maps of the country. He also identified the magnetic anomaly
Magnetic anomaly
In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material...

 located on the Iași
Iasi
Iași is the second most populous city and a municipality in Romania. Located in the historical Moldavia region, Iași has traditionally been one of the leading centres of Romanian social, cultural, academic and artistic life...

-Botoșani
Botosani
Botoșani is the capital city of Botoșani County, in northern Moldavia, Romania. Today, it is best known as the birthplace of many celebrated Romanians, including Mihai Eminescu and Nicolae Iorga.- Origin of the name :...

 line.

In 1947, Procopiu identified a variation of the Earth's magnetic field
Earth's magnetic field
Earth's magnetic field is the magnetic field that extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun...

, with a periodicity
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...

 of approximately 500 years, indicating that, starting 1932 Earth's magnetic moment
Magnetic moment
The magnetic moment of a magnet is a quantity that determines the force that the magnet can exert on electric currents and the torque that a magnetic field will exert on it...

 increases from the equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

 to the poles
Magnetic pole
Magnetic pole may refer to:* One of the two ends of a magnet* The magnetic poles of astronomical bodies, a special case of magnets, two special cases of which are the Geomagnetic poles:...

.

Main works