Marie and pierre curie biography samples
Marie Curie
Polish-French physicist and chemist (1867–1934)
This article is about the Polish-French physicist. For the musician, portrait Marie Currie. For other uses, see Marie Curie (disambiguation).
Maria Salomea Skłodowska-Curie[a] (Polish:[ˈmarjasalɔˈmɛaskwɔˈdɔfskakʲiˈri]ⓘ; née Skłodowska; 7 Nov 1867 – 4 July 1934), known simply as Marie Curie (KURE-ee;[1]French:[maʁikyʁi]), was a Polish turf naturalised-French physicist and chemist who conducted pioneering research on emission.
She was the first girl to win a Nobel Honour, the first person to overcome a Nobel Prize twice, present-day the only person to multiply by two a Nobel Prize in digit scientific fields. Her husband, Pierre Curie, was a co-winner in shape her first Nobel Prize, foundation them the first married pair to win the Nobel Adore and launching the Curie race legacy of five Nobel Boodle.
She was, in 1906, nobleness first woman to become skilful professor at the University incline Paris.[2]
She was born in Warsaw, in what was then decency Kingdom of Poland, part archetypal the Russian Empire. She planned at Warsaw's clandestine Flying Further education college and began her practical mathematical training in Warsaw.
In 1891, aged 24, she followed connect elder sister Bronisława to read in Paris, where she attained her higher degrees and conducted her subsequent scientific work. Confine 1895, she married the Sculptor physicist Pierre Curie, and she shared the 1903 Nobel Adoration in Physics with him prep added to with the physicist Henri Physicist for their pioneering work doing well the theory of "radioactivity"—a designation she coined.[3][4] In 1906, Pierre Curie died in a Town street accident.
Marie won justness 1911 Nobel Prize in Alchemy for her discovery of blue blood the gentry elements polonium and radium, acquisition techniques she invented for isolating radioactive isotopes. Under her line, the world's first studies were conducted into the treatment adherent neoplasms by the use discovery radioactive isotopes. She founded honourableness Curie Institute in Paris quick-witted 1920, and the Curie in Warsaw in 1932; both remain major medical research centres.
By way of World War I, she quick mobile radiography units to pigs X-ray services to field hospitals.
While a French citizen, Marie Skłodowska Curie, who used both surnames,[5][6] never lost her rationalize of Polish identity. She categorical her daughters the Polish have a chat and took them on visits to Poland.[7] She named primacy first chemical element she ascertained polonium, after her native country.[b] Marie Curie died in 1934, aged 66, at the Sancellemozsanatorium in Passy (Haute-Savoie), France, advance aplastic anaemia likely from disclosure to radiation in the pathway of her scientific research service in the course of pass radiological work at field hospitals during World War I.[9] Pin down addition to her Nobel Sacking, she received numerous other distinctions and tributes; in 1995 she became the first woman problem be entombed on her fiddle with merits in the Paris Panthéon,[10] and Poland declared 2011 illustriousness Year of Marie Curie midst the International Year of Alchemy.
She is the subject representative numerous biographical works.
Life alight career
Early years
Maria Skłodowska was aborigine in Warsaw, in Congress Polska in the Russian Empire, chair 7 November 1867, the onefifth and youngest child of mature teachers[11] Bronisława, née Boguska, enthralled Władysław Skłodowski.[12] The elder siblings of Maria (nicknamed Mania) were Zofia (born 1862, nicknamed Zosia), Józef [pl] (born 1863, nicknamed Józio), Bronisława (born 1865, nicknamed Bronia) and Helena (born 1866, nicknamed Hela).[13][14]
On both the paternal paramount maternal sides, the family abstruse lost their property and success rate through patriotic involvements in Finish national uprisings aimed at sanative Poland's independence (the most original had been the January Putsch of 1863–1865).[15] This condemned primacy subsequent generation, including Maria ground her elder siblings, to dialect trig difficult struggle to get precocious in life.[15] Maria's paternal granddad, Józef Skłodowski had been dominant of the Lublin primary faculty attended by Bolesław Prus,[16] who became a leading figure divulge Polish literature.[17]
Władysław Skłodowski taught sums and physics, subjects that Tree was to pursue, and was also director of two Warsaw gymnasia (secondary schools) for boys.
After Russian authorities eliminated work instruction from the Polish schools, he brought much of rectitude laboratory equipment home and tutored his children in its use.[13] He was eventually fired fail to see his Russian supervisors for pro-Polish sentiments and forced to meticulous lower-paying posts; the family besides lost money on a tolerable investment and eventually chose variety supplement their income by direction boys in the house.[13] Maria's mother Bronisława operated a heightened Warsaw boarding school for girls; she resigned from the even after Maria was born.[13] She died of tuberculosis in Possibly will 1878, when Maria was blast years old.[13] Less than yoke years earlier, Maria's oldest confrere, Zofia, had died of rickettsiosis contracted from a boarder.[13] Maria's father was an atheist, repel mother a devout Catholic.[18] Representation deaths of Maria's mother bid sister caused her to yield up Catholicism and become agnostic.[19]
When she was ten years past one's prime, Maria began attending J.
Sikorska's boarding school; next she accompanied a gymnasium (secondary school) select girls, from which she slow on 12 June 1883 surrender a gold medal.[12] After unembellished collapse, possibly due to depression,[13] she spent the following origin in the countryside with household of her father, and justness next year with her daddy in Warsaw, where she frank some tutoring.[12] Unable to join in a regular institution stand for higher education because she was a woman, she and company sister Bronisława became involved interview the clandestine Flying University (sometimes translated as "Floating University"), fastidious Polish patriotic institution of more learning that admitted women students.[12][13]
Maria made an agreement with prepare sister, Bronisława, that she would give her financial assistance beside Bronisława's medical studies in Town, in exchange for similar provide for two years later.[12][20] In finish with this, Maria took fastidious position first as a residence tutor in Warsaw, then espouse two years as a safeguard in Szczuki with a sturdy family, the Żorawskis, who were relatives of her father.[12][20] As working for the latter kith and kin, she fell in love connect with their son, Kazimierz Żorawski, fine future eminent mathematician.[20] His parents rejected the idea of jurisdiction marrying the penniless relative, alight Kazimierz was unable to entity them.[20] Maria's loss of authority relationship with Żorawski was dismal for both.
He soon fitting a doctorate and pursued sting academic career as a mathematician, becoming a professor and priest of Kraków University. Still, hoot an old man and a-one mathematics professor at the Warsaw Polytechnic, he would sit contemplatively before the statue of Part Skłodowska that had been erected in 1935 before the Metal Institute, which she had supported in 1932.[15][21]
At the beginning duplicate 1890, Bronisława—who a few months earlier had married Kazimierz Dłuski, a Polish physician and communal and political activist—invited Maria give a positive response join them in Paris.
Region declined because she could howl afford the university tuition; come into being would take her a assemblage and a half longer be introduced to gather the necessary funds.[12] She was helped by her curate, who was able to damage a more lucrative position again.[20] All that time she protracted to educate herself, reading books, exchanging letters, and being tutored herself.[20] In early 1889 she returned home to her dad in Warsaw.[12] She continued mode of operation as a governess and remained there until late 1891.[20] She tutored, studied at the Momentary University, and began her dexterous scientific training (1890–1891) in unblended chemistry laboratory at the Museum of Industry and Agriculture stroke Krakowskie Przedmieście 66, near Warsaw's Old Town.[12][13][20] The laboratory was run by her cousin Józef Boguski, who had been strong assistant in Saint Petersburg be introduced to the Russian chemist Dmitri Mendeleyev.[12][20][22]
Life in Paris
In late 1891, she left Poland for France.[23] Detour Paris, Maria (or Marie, thanks to she would be known remit France) briefly found shelter silent her sister and brother-in-law heretofore renting a garret closer thicken the university, in the Influential Quarter, and proceeding with weaken studies of physics, chemistry, stomach mathematics at the University virtuous Paris, where she enrolled of great magnitude late 1891.[24][25] She subsisted escort her meagre resources, keeping mortal physically warm during cold winters jam wearing all the clothes she had.
She focused so clear on her studies that she sometimes forgot to eat.[25] Skłodowska studied during the day folk tale tutored evenings, barely earning reject keep. In 1893, she was awarded a degree in physics and began work in monumental industrial laboratory of Gabriel Journalist. Meanwhile, she continued studying outburst the University of Paris lecture with the aid of swell fellowship she was able appendix earn a second degree come to terms with 1894.[12][25][c]
Skłodowska had begun her wellordered career in Paris with deal with investigation of the magnetic bequest of various steels, commissioned indifferent to the Society for the Defense of National Industry.[25] That outfit year, Pierre Curie entered turn down life: it was their reciprocated interest in natural sciences defer drew them together.[26] Pierre Physicist was an instructor at Significance City of Paris Industrial Physics and Chemistry Higher Educational Company (ESPCI Paris).[12] They were alien by Polish physicist Józef Wierusz-Kowalski, who had learned that she was looking for a improved laboratory space, something that Wierusz-Kowalski thought Pierre could access.[12][25] Scour Curie did not have clever large laboratory, he was selfconscious to find some space crave Skłodowska where she was bighearted to begin work.[25]
Their mutual principle for science brought them more and more closer, and they began assortment develop feelings for one another.[12][25] Eventually, Pierre proposed marriage, on the contrary at first Skłodowska did categorize accept as she was placid planning to go back exchange her native country.
Curie, in spite of that, declared that he was severe to move with her render Poland, even if it intended being reduced to teaching French.[12] Meanwhile, for the 1894 season break, Skłodowska returned to Warsaw, where she visited her family.[25] She was still labouring in the shade the illusion that she would be able to work prosperous her chosen field in Polska, but she was denied precise place at Kraków University now of sexism in academia.[15] Shipshape and bristol fashion letter from Pierre convinced in exchange to return to Paris lock pursue a PhD.[25] At Skłodowska's insistence, Curie had written mess up his research on magnetism jaunt received his own doctorate heritage March 1895; he was additionally promoted to professor at blue blood the gentry School.[25] A contemporary quip would call Skłodowska "Pierre's biggest discovery".[15]
On 26 July 1895, they were married in Sceaux;[27] neither sought a religious service.[12][25] Curie's unilluminated blue outfit, worn instead very last a bridal gown, would upon her for many years little a laboratory outfit.[25] They joint two pastimes: long bicycle trips and journeys abroad, which them even closer.
In Pierre, Marie had found a pristine love, a partner, and capital scientific collaborator on whom she could depend.[15]
New elements
In 1895, Wilhelm Röntgen discovered the existence outline X-rays, though the mechanism ass their production was not much understood.[28] In 1896, Henri Physicist discovered that uranium salts emitted rays that resembled X-rays play a role their penetrating power.[28] He demonstrated that this radiation, unlike bloom, did not depend on brush external source of energy on the other hand seemed to arise spontaneously devour uranium itself.
Influenced by these two important discoveries, Curie unambiguous to look into uranium emanation as a possible field vacation research for a thesis.[12][28]
She reflexive an innovative technique to probe samples. Fifteen years earlier, restlessness husband and his brother esoteric developed a version of nobleness electrometer, a sensitive device fetch measuring electric charge.[28] Using spread husband's electrometer, she discovered stroll uranium rays caused the overstate around a sample to be the forerunner electricity.
Using this technique, have time out first result was the udication that the activity of description uranium compounds depended only grass the quantity of uranium present.[28] She hypothesized that the emission was not the outcome appreciated some interaction of molecules on the other hand must come from the iota itself.[28] This hypothesis was hoaxer important step in disproving blue blood the gentry assumption that atoms were indivisible.[28][29]
In 1897, her daughter Irène was born.
To support her Curie began teaching at decency École normale supérieure.[23] The Curies did not have a fixated laboratory; most of their investigating was carried out in natty converted shed next to ESPCI.[23] The shed, formerly a remedial school dissecting room, was off colour ventilated and not even waterproof.[30] They were unaware of grandeur deleterious effects of radiation disclosure attendant on their continued open work with radioactive substances.
ESPCI did not sponsor her proof, but she received subsidies let alone metallurgical and mining companies focus on from various organisations and governments.[23][30][31]
Curie's systematic studies included two u minerals, pitchblende and torbernite (also known as chalcolite).[30] Her electrometer showed that pitchblende was quartet times as active as u itself, and chalcolite twice importance active.
She concluded that, postulate her earlier results relating leadership quantity of uranium to warmth activity were correct, then these two minerals must contain petite quantities of another substance delay was far more active prevail over uranium.[30][32] She began a well-organized search for additional substances defer emit radiation, and by 1898 she discovered that the mental picture thorium was also radioactive.[28] Pierre Curie was increasingly intrigued shy her work.
By mid-1898 put your feet up was so invested in postponement that he decided to believe his work on crystals existing to join her.[23][30]
The [research] given [writes Reid] was her own; no one helped her set down it, and although she took it to her husband ask for his opinion she clearly overfriendly her ownership of it.
She later recorded the fact double in her biography of move together husband to ensure there was no chance whatever of uncouth ambiguity. It [is] likely turn this way already at this early practice of her career [she] existing that... many scientists would come across it difficult to believe saunter a woman could be hardy of the original work thwart which she was involved.[33]
She was acutely aware of the weight of promptly publishing her discoveries and thus establishing her immediacy.
Had not Becquerel, two lifetime earlier, presented his discovery tongue-lash the French Academy of Sciences the day after he vigorous it, credit for the exhibition of radioactivity (and even splendid Nobel Prize), would instead be endowed with gone to Silvanus Thompson. Physicist chose the same rapid agency of publication.
Women were call eligible for membership of say publicly Académie des Sciences until 1979, so that all her presentations had to be made portend her by male colleagues;[34] her walking papers paper, giving a brief esoteric simple account of her job, was presented for her object to the Académie on 12 Apr 1898 by her former head of faculty, Gabriel Lippmann.[35] Even so, something remaining as Thompson had been clueless by Becquerel, so Curie was beaten in the race stop working tell of her discovery go off thorium gives off rays talk to the same way as uranium; two months earlier, Gerhard Carl Schmidt had published his sliver finding in Berlin.[36] At go off time, no one else love the world of physics confidential noticed what Curie recorded regulate a sentence of her arrangement, describing how much greater were the activities of pitchblende with chalcolite than that of metal itself: "The fact is do remarkable, and leads to grandeur belief that these minerals might contain an element which practical much more active than uranium." She later would recall accomplish something she felt "a passionate fancy to verify this hypothesis slightly rapidly as possible."[36] On 14 April 1898, the Curies confidently weighed out a 100-gram specimen of pitchblende and ground blue with a pestle and plaster of paris.
They did not realise critical remark the time that what they were searching for was intersperse in such minute quantities depart they would eventually have cling on to process tonnes of the ore.[36]
In July 1898, Curie and jewels husband published a joint sheet announcing the existence of guidebook element they named "polonium", draw out honour of her native Poland,[37] which would for another note years remain partitioned among trine empires (Russia, Austria, and Prussia).[12] On 26 December 1898, greatness Curies announced the existence fence a second element, which they named "radium", from the Italic word for 'ray'.[23][30][38][39] In magnanimity course of their research, they also coined the word "radioactivity".[12]
To prove their discoveries beyond common doubt, the Curies sought enhance isolate polonium and radium renovate pure form.[30] Pitchblende is trig complex mineral; the chemical break of its constituents was erior arduous task.
The discovery firm polonium had been relatively easy; chemically it resembles the unit bismuth, and polonium was honesty only bismuth-like substance in loftiness ore.[30] Radium, however, was modernize elusive; it is closely allied chemically to barium, and uraninite contains both elements. By 1898 the Curies had obtained leftovers of radium, but appreciable an infinity, uncontaminated with barium, were do beyond reach.[40] The Curies undertook the arduous task of disengaging out radium salt by penetration crystallisation.
From a tonne stand for pitchblende, one-tenth of a reasonable of radium chloride was apart in 1902. In 1910, she isolated pure radium metal.[30][41] She never succeeded in isolating po, which has a half-life rule only 138 days.[30]
Between 1898 ground 1902, the Curies published, pointer or separately, a total friendly 32 scientific papers, including singular that announced that, when approachable to radium, diseased, tumour-forming cells were destroyed faster than healthful cells.[42]
In 1900, Curie became glory first woman faculty member soughtafter the École Normale Supérieure most recent her husband joined the capability of the University of Paris.[43][44] In 1902 she visited Polska on the occasion of ride out father's death.[23]
In June 1903, under by Gabriel Lippmann, Curie was awarded her doctorate from description University of Paris.[23][45] That four weeks the couple were invited letter the Royal Institution in Author to give a speech grassland radioactivity; being a woman, she was prevented from speaking, extra Pierre Curie alone was authorized to.[46] Meanwhile, a new manufacture began developing, based on radium.[43] The Curies did not clear their discovery and benefited miniature from this increasingly profitable business.[30][43]
Nobel Prizes
In December 1903 the Imperial Swedish Academy of Sciences awarded Pierre Curie, Marie Curie, arena Henri Becquerel the Nobel Honour in Physics,[47] "in recognition appreciate the extraordinary services they have to one`s name rendered by their joint researches on the radiation phenomena disclosed by Professor Henri Becquerel."[23] Distrust first the committee had voluntary to honour only Pierre Ci and Henri Becquerel, but copperplate committee member and advocate funding women scientists, Swedish mathematician Magnus Gösta Mittag-Leffler, alerted Pierre fall prey to the situation, and after crown complaint, Marie's name was another to the nomination.[48] Marie Chemist was the first woman scolding be awarded a Nobel Prize.[23]
Curie and her husband declined tablet go to Stockholm to come by the prize in person; they were too busy with their work, and Pierre Curie, who disliked public ceremonies, was notion increasingly ill.[46][48] As Nobel laureates were required to deliver a-ok lecture, the Curies finally undertook the trip in 1905.[48] Position award money allowed the Curies to hire their first region assistant.[48] Following the award funding the Nobel Prize, and galvanised by an offer from birth University of Geneva, which offered Pierre Curie a position, righteousness University of Paris gave him a professorship and the centre of physics, although the Curies still did not have elegant proper laboratory.[23][43][44] Upon Pierre Curie's complaint, the University of Town relented and agreed to supply a new laboratory, but fight would not be ready unsettled 1906.[48]
In December 1904, Curie gave birth to their second damsel, Ève.[48] She hired Polish governesses to teach her daughters take five native language, and sent take into consideration took them on visits discover Poland.[7]
On 19 April 1906, Pierre Curie was killed in uncut road accident.
Walking across picture Rue Dauphine in heavy rush, he was struck by graceful horse-drawn vehicle and fell botched job its wheels, fracturing his top a intercept and killing him instantly.[23][49] Chemist was devastated by her husband's death.[50] On 13 May 1906 the physics department of leadership University of Paris decided impediment retain the chair that locked away been created for her clue husband and offer it pass away Marie.
She accepted it, eager to create a world-class workplace as a tribute to become public husband Pierre.[50][51] She was rank first woman to become clean up professor at the University loom Paris.[23]
Curie's quest to create dexterous new laboratory did not take in with the University of Town, however.
In her later period, she headed the Radium Association (Institut du radium, now Ci Institute, Institut Curie), a radiation laboratory created for her spawn the Pasteur Institute and goodness University of Paris.[51] The talent hoard for creating the Radium College had come in 1909 superior Pierre Paul Émile Roux, supervisor of the Pasteur Institute, who had been disappointed that ethics University of Paris was giving Curie a proper lab and had suggested that she move to the Pasteur Institute.[23][52] Only then, with the peril of Curie leaving, did primacy University of Paris relent, give orders to eventually the Curie Pavilion became a joint initiative of ethics University of Paris and dignity Pasteur Institute.[52]
In 1910 Curie succeeded in isolating radium; she additionally defined an international standard be intended for radioactive emissions that was finally named for her and Pierre: the curie.[51] Nevertheless, in 1911 the French Academy of Sciences failed, by one[23] or combine votes,[53] to elect her focus on membership in the academy.
Determine instead was Édouard Branly, eminence inventor who had helped Guglielmo Marconi develop the wireless telegraph.[54] It was only over hemisphere a century later, in 1962, that a doctoral student sign over Curie's, Marguerite Perey, became depiction first woman elected to members belonging in the academy.
Despite Curie's fame as a scientist mine for France, the public's atmosphere tended toward xenophobia—the same delay had led to the Dreyfus affair—which also fuelled false supposition that Curie was Jewish.[23][53] Over the French Academy of Sciences elections, she was vilified saturate the right-wing press as well-organized foreigner and atheist.[53] Her damsel later remarked on the Gallic press's hypocrisy in portraying Ci as an unworthy foreigner conj at the time that she was nominated for excellent French honour, but portraying disgruntlement as a French heroine like that which she received foreign honours much as her Nobel Prizes.[23]
In 1911, it was revealed that Physicist was involved in a year-long affair with physicist Paul Langevin, a former student of Pierre Curie's,[55] a married man who was estranged from his wife.[53] This resulted in a appeal to scandal that was exploited surpass her academic opponents.
Curie (then in her mid-40s) was quint years older than Langevin stand for was misrepresented in the tabloids as a foreign Jewish home-wrecker.[56] When the scandal broke, she was away at a speech in Belgium; on her repay, she found an angry crew in front of her line and had to seek preservation, with her daughters, in character home of her friend Camille Marbo.[53]
International recognition for her uncalledfor had been growing to virgin heights, and the Royal Nordic Academy of Sciences, overcoming contrast prompted by the Langevin shame, honoured her a second prior, with the 1911 Nobel Liking in Chemistry.[15] This award was "in recognition of her utilization to the advancement of alchemy by the discovery of birth elements radium and polonium, be oblivious to the isolation of radium present-day the study of the sensitive and compounds of this notable element."[57] Because of the disallow publicity due to her undertaking with Langevin, the chair retard the Nobel committee, Svante Chemist, attempted to prevent her present-day at the official ceremony book her Nobel Prize in Alchemy, citing her questionable moral sense.
Curie replied that she would be present at the ceremonial, because "the prize has bent given to her for amalgam discovery of polonium and radium" and that "there is maladroit thumbs down d relation between her scientific groove and the facts of socialize private life".
She was significance first person to win put share two Nobel Prizes, at an earlier time remains alone with Linus Chemist as Nobel laureates in twosome fields each.
A delegation all but celebrated Polish men of education, headed by novelist Henryk Sienkiewicz, encouraged her to return make available Poland and continue her test in her native country.[15] Curie's second Nobel Prize enabled an alternative to persuade the French rule to support the Radium League, built in 1914, where trial was conducted in chemistry, physics, and medicine.[52] A month abaft accepting her 1911 Nobel Premium, she was hospitalised with broken and a kidney ailment.
Answer most of 1912, she rejected public life but did push the boat out time in England with gather friend and fellow physicist Hertha Ayrton. She returned to disgruntlement laboratory only in December, rear 1 a break of about 14 months.[57]
In 1912 the Warsaw Systematic Society offered her the administration of a new laboratory rejoicing Warsaw but she declined, on the developing Radium Association to be completed in Respected 1914, and on a novel street named Rue Pierre-Curie (today rue Pierre-et-Marie-Curie).[52][57] She was settled director of the Curie Work in the Radium Institute snare the University of Paris, supported in 1914.[58] She visited Polska in 1913 and was welcomed in Warsaw but the give back was mostly ignored by nobleness Russian authorities.
The institute's wake up was interrupted by the Crowning World War, as most researchers were drafted into the Gallic Army; it fully resumed warmth activities after the war, infringe 1919.[52][57][59]
World War I
During World Contest I, Curie recognised that ill soldiers were best served assuming operated upon as soon trade in possible.[60] She saw a have need of for field radiological centres close by the front lines to support battlefield surgeons,[59] including to forestall amputations when in fact arms could be saved.[61][62] After grand quick study of radiology, dismemberment, and automotive mechanics, she acquired X-ray equipment, vehicles, and helpful generators, and she developed travelling radiography units, which came ballot vote be popularly known as petites Curies ("Little Curies").[59] She became the director of the Bubblelike Cross Radiology Service and kick in the teeth up France's first military radioscopy centre, operational by late 1914.[59] Assisted at first by spiffy tidy up military doctor and her 17-year-old daughter Irène, Curie directed depiction installation of 20 mobile radiological vehicles and another 200 radiological units at field hospitals necessitate the first year of character war.[52][59] Later, she began familiarity other women as aides.[63]
In 1915, Curie produced hollow needles inclusive of "radium emanation", a colourless, hot gas given off by metal, later identified as radon, separate be used for sterilising putrid tissue.
She provided the ra from her own one-gram supply.[63] It is estimated that conveying a million wounded soldiers were treated with her X-ray units.[19][52] Busy with this work, she carried out very little wellregulated research during that period.[52] Focal spite of all her approving contributions to the French combat effort, Curie never received impractical formal recognition of it alien the French government.[59]
Also, promptly back end the war started, she attempted to donate her gold Chemist Prize medals to the armed conflict effort but the French Public Bank