id
stringlengths
40
40
title
stringlengths
15
120
text
stringlengths
41
3.14k
source
stringclasses
2 values
6d3424d308c446b0f33edf6d12d71febc82e99ec
emmett reid dunn (november 21, 1894 – february
emmett reid dunn (november 21, 1894 – february 13, 1956) was an american herpetologist and educator noted for his work in panama and for studies of salamanders in the eastern united states.
wikipedia
fd90914de7a30518676015813eb19b9a66b98dfb
helen h. fielding is a professor of physical
helen h. fielding is a professor of physical chemistry at university college london (ucl). she focuses on ultrafast transient spectroscopy of protein chromophores and molecules. she was the first woman to win the royal society of chemistry (rsc) harrison-meldola memorial prize (1996) and marlow award (2001).
wikipedia
607c3c6a68373db2b6232e39b02b15b6e69d57bb
she has worked extensively on ultrafast chemical biology
she has worked extensively on ultrafast chemical biology in the gas phase. fielding developed time-resolved photoelectron spectroscopy to study the relaxation dynamics of photoexcited molecules. she has investigated the intramolecular dynamics of vibrationally and electronically excited benzene, and demonstrated new el...
wikipedia
d9b44c1dc6b3c93ff1c25bfee264d2bcd3cd62ed
fielding was made an epsrc advanced research fellow
fielding was made an epsrc advanced research fellow in 2001, and was the first woman to be awarded the royal society of chemistry marlow medal. in 2003 fielding moved to university college london, where she leads a large laser laboratory. her recent research has focussed on the dynamics of excited states formed during ...
wikipedia
e2490cdaee84d77fad2f4f94724a2881961cfb7c
she made the first observation of a wave
she made the first observation of a wave packet in a rydberg molecule in 2000. this observation made her interested in coherent control, looking to exploit the phase of a rotating rydberg molecule to manipulate the dynamics of chemical systems. she explored the decay pathways of the rydberg molecule no. fielding used t...
wikipedia
3da3808ddd7112de757e063d7f9a3352f36fe7d6
fielding was appointed a lecturer at king's college
fielding was appointed a lecturer at king's college london in 1994 after only 18 months of postdoctoral work. she was the first woman to be awarded the harrison-meldola memorial prize in 1996. she is interested in how to excite electron functions coherently, generating a wave packets with a localised probability distri...
wikipedia
b3f95d22b60737ceb8b22e715426f2baa580553b
fielding was a scientist at the national physical
fielding was a scientist at the national physical laboratory from 1992 to 1993. in 1993 she joined the university of amsterdam as a postdoctoral fellow, working with ben van linden van den heuvell. here she worked on rydberg wave packets in coulombic and magnetic fields.
wikipedia
b877e543402d60bc30f93edb233fd33f84e43c56
fielding studied the natural sciences tripos at the
fielding studied the natural sciences tripos at the university of cambridge. she began her phd at the university of cambridge, working with timothy softley, but moved with him to the university of oxford where they studied excited quantum states using photoelectron spectroscopy. she was awarded her doctor of philosophy...
wikipedia
717162e2e891d9479d433f5bfea8bd4e07545d58
helen h. fielding frsc finstp cphys cchem is
helen h. fielding frsc finstp cphys cchem is a professor of physical chemistry at university college london (ucl). she focuses on ultrafast transient spectroscopy of protein chromophores and molecules. she was the first woman to win the royal society of chemistry (rsc) harrison-meldola memorial prize (1996) and marlow ...
wikipedia
33aedf3b7eeb7b4484768d7944d17306068cb7e7
sara josephine baker was an american physician notable
sara josephine baker was an american physician notable for making contributions to public health, especially in the immigrant communities of new york city. her fight against the damage that widespread urban poverty and ignorance caused to children, especially newborns, is perhaps her most lasting legacy. in 1917, she n...
wikipedia
c627229a83e4e815ae2b849bde7d015c11297396
in 1923, baker retired, but she did not
in 1923, baker retired, but she did not stop working. she became the first woman to be a professional representative to the league of nations when she served on the health committee for the united states from 1922 to 1924. she was also active in many groups and societies including over twenty-five medical societies and...
wikipedia
32c99393b98f07cbbe16dc1f10a8a0719bd657fc
baker spent much of the later part of
baker spent much of the later part of her life with ida alexa ross wylie, a novelist, essayist, and hollywood scriptwriter from australia who identified as a "woman-oriented woman". when baker retired in 1923, she started to run their household while writing her autobiography, fighting for life. in 1935 and four years ...
wikipedia
fbdb38d942cc2bc07ac92eba7ae75eae47c714cc
after the united states entered world war i,
after the united states entered world war i, baker became even better known. most of this publicity was generated from her comment to a new york times reporter. she told him that it was "six times safer to be soldier in the trenches of france than to be a baby born in the united states." she was able to start a lunch p...
wikipedia
0571e9019fc4a4ddbc4fadfdbbbbc816d17b1678
josephine baker was becoming famous, so much so
josephine baker was becoming famous, so much so that new york university medical school asked her to lecture there on children's health, or "child hygiene", as it was known at the time. baker said she would if she could also enroll in the school. the school initially turned her down, but eventually acquiesced after loo...
wikipedia
8843b1f115206750f251151dfaff1448c616f64c
early in her career, baker had twice helped
early in her career, baker had twice helped to catch mary mallon, also known as "typhoid mary". mallon was the first known healthy carrier of typhoid, who instigated several separate outbreaks of the disease and is known to have infected more than 50 people through her job as a cook. at least three of the people she in...
wikipedia
315b0ab7d557e08efe62da0a6ee925d34a045e50
while baker was campaigning to license midwives, treat
while baker was campaigning to license midwives, treat blindness, encourage breastfeeding, provide safe pasteurized milk, and educate mothers, older children were still getting sick and malnourished. baker worked to make sure each school had its own doctor and nurse, and that the children were routinely checked for inf...
wikipedia
1ff78a2a12ff93890a8adda98a4ccf23d1ee55e8
through josephine baker's efforts, infants were much safer
through josephine baker's efforts, infants were much safer than they had been the previous year; blindness decreased from 300 babies per year to 3 per year. but there was still one area where infancy was dangerous: at birth. babies were often delivered by midwives, who were excluded from the formal training available t...
wikipedia
e5a8c53a7c59216471efc6175655e0bd5b1f5b9c
baker aided in the prevention of infant blindness,
baker aided in the prevention of infant blindness, a scourge caused by gonorrhea bacteria transmitted during birth. to prevent blindness, babies were given drops of silver nitrate in their eyes. before baker arrived, the bottles in which the silver nitrate was kept would often become unsanitary or would contain doses t...
wikipedia
24f06a901504948066e1cd250947b2752767bd7c
baker and a group of nurses started to
baker and a group of nurses started to train mothers in how to care for their babies: how to clothe infants to keep them from getting too hot, how to feed them a good diet, how to keep them from suffocating in their sleep, and how to keep them clean. she set up a milk station where clean milk was given out. commercial ...
wikipedia
ddd9ae93f2bfe1c2e5de5ab716dbb945429e6ac0
after working diligently in the school system, baker
after working diligently in the school system, baker was offered an opportunity to help lower the mortality rate in hell's kitchen. it was considered the worst slum in new york at the turn of the century, with as many as 4,500 people dying every week. baker decided to focus on the infant mortality rate in particular, a...
wikipedia
75906af87c8e7fd027be9a08330f431d1d399bd2
the way to keep people from dying from
the way to keep people from dying from disease, it struck me suddenly, was to keep them from falling ill. healthy people don't die. it sounds like a completely witless remark, but at that time it was a startling idea. preventative medicine had hardly been born yet and had no promotion in public health work.
wikipedia
7dae60c04e982fb5d2bdf837cc1acc86cc24e281
baker began practicing as a private physician in
baker began practicing as a private physician in new york city following her internship. in 1901, baker passed the civil service exam and qualified to be a medical inspector at the department of health, and worked as a part-time inspector in 1902. known as "dr. joe," she wore masculine-tailored suits and joked that col...
wikipedia
8d16c6886874707379e3cb594d94e8e44e743248
after studying chemistry and biology at home, she
after studying chemistry and biology at home, she enrolled in the new york infirmary medical college, a medical school for women, founded by the sisters and physicians elizabeth blackwell and emily blackwell. the only class she failed—"the normal child", taught by anne daniel —led to her fascination with the future rec...
wikipedia
b56584dbf51d978cfe68d6ec77535240dde5ba82
baker was born in poughkeepsie, new york, in
baker was born in poughkeepsie, new york, in 1873 to a wealthy quaker family. after her father and brother died of typhoid, baker felt pressure to support her mother and sister financially. so, at the age of 16, baker decided on a career in medicine.
wikipedia
30f2bb8da8de4966d6fe986f4fb0ae47a0248df4
sara josephine baker (november 15, 1873 – february
sara josephine baker (november 15, 1873 – february 22, 1945) was an american physician notable for making contributions to public health, especially in the immigrant communities of new york city. her fight against the damage that widespread urban poverty and ignorance caused to children, especially newborns, is perhaps...
wikipedia
86e722918dc2a8f26bdaee3f1a184c370210eca5
gerhard wilhelm goetze was a german-born ph.d. researcher
gerhard wilhelm goetze was a german-born ph.d. researcher and inventor in atomic physics. he was primarily known for his work on the moon-to-earth apollo tv camera making live broadcast in both brilliant sunlight and pitch darkness possible. goetze discovered the secondary electron conduction (sec) effect which amplifi...
wikipedia
c9a62d7a8a72ad5d89b4f063a42f4f15e4ae7e84
the sec tube was used on the orbiting
the sec tube was used on the orbiting astronomical observatory as the main sensor, on apollo 9, 10, 11, 12, and 13, in the atm satellites as well as the oso-h and sas-d space projects.
wikipedia
2d37d24ec7ab320b5178a3d4bd003b7d798bb912
the sec tube was used to build a
the sec tube was used to build a camera to transmit live images from the moon to earth on apollo 11. the tube was also employed in science in electron microscope biological tissue study; ground-based astronomy, material testing and inspection of integral circuits in industry, and security and police.
wikipedia
1a59feefc8089f989e945f4b0a9bc2acf835d9c3
the sec tube had dod highly top secret
the sec tube had dod highly top secret security classification but was the only device that could meet the apollo camera mission requirements to operate in both lunar day and night. the dod was asked to allow westinghouse the use of the sec tube for the apollo tv camera program. the task to develop this unique sec tube...
wikipedia
4aeb6a3853b1969b23ab740d9e147ab26d8d4f75
in the early 1960s in the pittsburgh research
in the early 1960s in the pittsburgh research laboratories the sec (secondary electron conduction) effect was discovered by goetze. this was developed for the department of defense (dod) for night vision in vietnam. it had the capability to produce clear images in motion at low light levels without motion distortion.
wikipedia
f35f6d1b8df3a4710713041bba261f76c81c737f
in october 1960 at the fifth international congress
in october 1960 at the fifth international congress on high speed photography, a. anderson, manager of the applied physics department of westinghouse research laboratories stated that, "a new electronic tube, so sensitive it can 'see' individual particles of light, has enabled westinghouse scientists to photograph the ...
wikipedia
318b51296535bf3ab2c76a767bf89b914311a69a
he continued his joy for flying his entire
he continued his joy for flying his entire life. his last aircraft, a 1960 single engine cessna 182 skylane was flown in 2007 after his death by his two sons, frank, senior pilot for fedex and thomas, mechanical engineer, across the atlantic ocean over 10 days and 40 flight hours from kassel airport, germany to beaver ...
wikipedia
765ba61cc0395f1b83ed698529f2acddec106429
while living in elmira, new york, goetze spent
while living in elmira, new york, goetze spent many weekends with his family at the harris hill soaring club pursuing his hobby as a sailplane pilot. in 1969 goetze traveled to pikes peak near colorado springs, colorado for the final qualifying test for the prestigious 3 diamond badge in gliding from the fai gliding co...
wikipedia
cdb2269a40ba8269a313c54cf251b56df56651d2
goetze's passion in life was for gliding. he
goetze's passion in life was for gliding. he began his interest at the blaue kuppe in the countryside of the werra-meißner area. goetze was one of the early members (1964) of the eschwege luftsportverrein (local glider soaring club).
wikipedia
5a0f3168115ae98171fce81e626bcb6da115e5cb
in 1981 goetze headed fanal elektric, an electronic
in 1981 goetze headed fanal elektric, an electronic components manufacturer in germany, who sold 95% of its stock shares to westinghouse to secure the american market. in 1989, goetze along with other investors, purchased fanal elektric from westinghouse and grew fanal with 3 other firms; hundt & weber, maihak aktienge...
wikipedia
9234aa113c26850b80a979a97facec340b9adf0d
in 1964, he moved with his wife and
in 1964, he moved with his wife and five children to elmira, new york, to continue his work at the westinghouse cathode ray tube facility in nearby horseheads, new york. as operations manager, goetze grew the department from a team of six to more than 170 scientists and staff. his work through westinghouse was an integ...
wikipedia
d06de0740c718994342f28f21f61edba923ffbb1
in the summer of 1959 the family moved
in the summer of 1959 the family moved to monroeville, pennsylvania, where goetze worked for the westinghouse electric corporation research and development laboratories in pittsburgh. his early research on night vision was initially classified for the department of defense. it was later declassified by the federal gove...
wikipedia
84651a697718cd6bbeb73a91f3871deb83139071
goetze traveled from germany to new york in
goetze traveled from germany to new york in january 1959 with his pregnant wife and two children under the sponsorship of the united states department of the army in the national interest. they lived for several months in the alamac hotel on broadway and west 71st street in new york city until employment was found.
wikipedia
9fe37847c463f60c11232d59f683dd7e1a4ad2ff
in 1954, gerhard married lisa herta kohlus of
in 1954, gerhard married lisa herta kohlus of eschwege. they had five children, two born in the convent of vincent de paul in eschwege, germany; regina karin and martin gerhard and three children born in wilkinsburg, pennsylvania, us; frank walter, arleen susan and thomas wilhelm. their marriage ended in divorce.
wikipedia
22871416d9f37f3fb11baaa2fec60aec087943b5
his concentration in nuclear physics led to his
his concentration in nuclear physics led to his doctoral thesis in zerfallsschema und beta-spektrum des msth1 (ra228) (disintegration schematic and beta spectrum of mesothorium) (isotopes of radium). goetze later found electrons to be more interesting and continued his work in atomic physics.
wikipedia
21d7de8ab5653487cfe11b445e7921738cbb3461
from 1949 to 1958 goetze studied and taught
from 1949 to 1958 goetze studied and taught physics at the university of marburg. in 1951, he became a member of one of the oldest academic fraternities, the german student corps, saxonia, founded in 1886, with the motto in treue fest or "in loyalty firm".
wikipedia
6b7d9e3afb777f6842540ec2fbe9a68af0ed40ea
goetze, along with his mother and baby sister,
goetze, along with his mother and baby sister, fled bartenstein, now named bartoszyce, on the last train on january 22, 1945, during the evacuation of east prussia. they made their way back to the family home in niederdünzebach. gerhard attended the gymnasium or college preparatory school, the friedrich-wilhelm schule ...
wikipedia
25709901ce32f83ffa746224229b8956408a674c
gerhard w. goetze was born in niederdünzebach near
gerhard w. goetze was born in niederdünzebach near eschwege, hessen, germany on june 19, 1930, to walter kurt götze, a businessman, and anna katherine sieland. he attended the local primary school until his father was transferred to bartenstein, near königsberg, east prussia, germany to work at the local volksschule (p...
wikipedia
250756d503104595a477dbdf376f882d5da7aced
in 1973 goetze received a franklin institute award,
in 1973 goetze received a franklin institute award, the longstreth medal established in 1890, for the conception and development of the sec tube, which played an important role in television, night surveillance and ultraviolet astronomical observations.
wikipedia
ddc168804aff55b99066778f22a39e088d0bfb99
gerhard wilhelm goetze (june 19, 1930 – january
gerhard wilhelm goetze (june 19, 1930 – january 17, 2007) was a german-born ph.d. researcher and inventor in atomic physics. he was primarily known for his work on the moon-to-earth apollo tv camera making live broadcast in both brilliant sunlight and pitch darkness possible. goetze discovered the secondary electron co...
wikipedia
521deafbe37828019a17905af732692822a3d87b
rada went on to dukla prague in 2007,
rada went on to dukla prague in 2007, keeping three clean sheets in the first part of the 2007–08 czech 2. liga. rada played for dukla in the second division for four years before the club celebrated promotion to the top-flight gambrinus liga in 2011. rada was responsible for two of the visiting team's goals in august ...
wikipedia
f1203dab8db0d19a6930bf63cf0fc15ad6350143
rada started his footballing career at sparta prague,
rada started his footballing career at sparta prague, going out on loan in his younger years. he joined bohemians 1905 in the bohemian football league on a year-long loan in 2005, keeping a clean sheet in his first ever match in the czech third tier. however rada played just four league matches before moving on loan to...
wikipedia
8d88b5582ee50f640fa86bbc8b077c23659de2e9
baek jong-bum is a south korean professional footballer
baek jong-bum is a south korean professional footballer who plays as a goalkeeper for k league 1 club fc seoul. born in daejeon, he attended osan middle and high school, where he underwent training through fc seoul's development system. baek signed with the club in 2018 and made his debut professional appearance in the...
wikipedia
73959a83b8c685613e69d8844e6031b51dd256c8
baek made his debut professional appearance in the
baek made his debut professional appearance in the sixth round of the 2022 k league 1 season amid an outbreak of covid-19 among his team's squad, which faced off against jeju united fc on march 19. in the second half of the game, as defender jeong woo-jae was shooting, baek collided with the player's knee, resulting in...
wikipedia
a4255df67e2df31ba1d533011a452999c7f943e7
in a pool of 134 footballers, baek was
in a pool of 134 footballers, baek was one of 15 selected to advance directly into the k league 1 in 2018. he, along with four others, signed a 5-year contract with fc seoul, becoming the first of its players to have undergone the club's development system at both osan middle and high school.
wikipedia
d926ae72105471a09134fb0908c83a242d1ede1b
baek was admitted to osan middle school and
baek was admitted to osan middle school and played for the fc seoul u-15 team at the 33rd seoul football association president's cup in 2014. during the penalty shoot-out at the finals, he blocked seil middle school's final goal attempt, leading his team to a 5–4 victory. the team won its first championship in its seco...
wikipedia
05a3f2052c7a8544faf504d2be4af13b71e80e12
baek jong-bum was born on january 21, 2001,
baek jong-bum was born on january 21, 2001, in daejeon, south korea. he attended daejeon jungang elementary school and played in its football team. it competed in the 2012 hwarang daegi national youth soccer tournament and advanced into the finals; baek received the gk (goalkeeper) award for his performance in the comp...
wikipedia
3986790ab8f65678aac6cd7dc99f957dd27dad1c
baek jong-bum (korean: 백종범; born january 21, 2001)
baek jong-bum (korean: 백종범; born january 21, 2001) is a south korean professional footballer who plays as a goalkeeper for k league 1 club fc seoul. born in daejeon, he attended osan middle and high school, where he underwent training through fc seoul's development system. baek signed with the club in 2018 and made his...
wikipedia
89e26a31cb7a333576ca0a9bc62891ac730e3741
philip james devries is a tropical biologist whose
philip james devries is a tropical biologist whose research focuses on insect ecology and evolution, especially butterflies. his best-known work includes symbioses between caterpillars, ants and plants, and community level biodiversity of rainforest butterflies. devries is professor emeritus at the university of new or...
wikipedia
4a241bcbb42b64b9961877a62da1951b762404ef
for decades, devries was involved with natural history
for decades, devries was involved with natural history documentary films as a writer, scientific advisor and on-camera presenter for production companies such as national geographic, partridge films, oxford scientific films, and granada. fifteen of these documentaries have been televised globally by national geographic...
wikipedia
d05f488364525abb90841ae1d4b50593f60993c7
devries discovered the substrate-borne calls produced by caterpillars
devries discovered the substrate-borne calls produced by caterpillars that form symbioses with ants in the butterfly families riodinidae and lycaenidae. in these symbioses, ants provide protection against arthropod predators in exchange for food secretions. devries demonstrated experimentally that the calls produced by...
wikipedia
e590109d80185e72f99c2f611e55e25848929708
recent honors include: in 2010, devries was elected
recent honors include: in 2010, devries was elected one of 125 extraordinary university of texas ex-graduates for the university's 125th anniversary; in 2012, the main-belt minor planet 89131 phildevries was named in devries' honor by astronomer bill yeung.
wikipedia
a3e751bb7911f99f210d2e0e2c3353e58d41cfbb
he is presently a professor at the university
he is presently a professor at the university of new orleans in louisiana, along with his wife and close colleague carla penz. devries continues to study long-term butterfly community diversity, and speciation. his butterfly trapping methods are used widely in tropical diversity studies and conservation efforts. he als...
wikipedia
8fb5f7593b38a6b60d2337bc44f3f6b8c4f60032
devries was an assistant professor at the university
devries was an assistant professor at the university of oregon (1994–2000), where he developed trapping methods to accrue long-term data sets on tropical butterfly communities. work with his colleague russell lande produced some of the first rigorous insights into the spatial and temporal dynamics of diverse rainforest...
wikipedia
81694ff411166534f9a41ad6169f6d24a30f8741
he was a pre-doctoral (1985–1986) and post-doctoral fellow
he was a pre-doctoral (1985–1986) and post-doctoral fellow (1987–1988) at the smithsonian tropical research institute, panama, a visiting scholar at the university of oxford, uk (1990–1991), an associate of the center for conservation biology at stanford university (1990–1992), and a geraldine r. dodge foundation fello...
wikipedia
8b7bd92f1c293e86617711feaed037cdf902669f
in 1988, devries received a macarthur fellowship that
in 1988, devries received a macarthur fellowship that allowed him to travel broadly in pursuit of tropical biology in costa rica, panama, ecuador, and argentina. through the macarthur fellows program, he became close friends with the artists lee friedlander, steve lacy, john t. scott, brad leithauser, and the historian...
wikipedia
d8275fb32a0853436c308489f498ec9da857070d
devries attended the university of texas at austin
devries attended the university of texas at austin from 1980 to 1987, where he earned a phd in zoology. his doctoral work focused on the widespread symbioses between butterfly caterpillars, ants and plants, which he popularized under the nickname " singing caterpillars ". in 1982, devries received a fellowship from the...
wikipedia
a1689fbc71fcda276efb9c38b60c19dbf5614df8
from 1975 to 1980, he was a curator
from 1975 to 1980, he was a curator of lepidoptera at the museo nacional de costa rica as a peace corps volunteer where he built the country's first major butterfly collection. devries traveled widely in costa rica, collecting and making observations on butterflies. this eventually provided a large body of information ...
wikipedia
8aeb0ff6b68f780cd4a9137520d41d6055b92b1a
devries was born in detroit, michigan to henry
devries was born in detroit, michigan to henry william devries and helen mary devries (née brnabic). his early interest in biology was nourished by close contact with nature during his childhood in rural michigan. as an undergraduate student at the university of michigan, ann arbor, devries was mentored in botany by pr...
wikipedia
dee51fb3e44e9dc7e954d1a5006089d2e950a0e6
philip james devries (born march 7, 1952) is
philip james devries (born march 7, 1952) is a tropical biologist whose research focuses on insect ecology and evolution, especially butterflies. his best-known work includes symbioses between caterpillars, ants and plants, and community level biodiversity of rainforest butterflies. devries is professor emeritus at the...
wikipedia
1ff1cf0d0d8316d9b9ac6559fe74bccbfd33c084
polyacetylene usually refers to an organic polymer with
polyacetylene usually refers to an organic polymer with the repeating unit [c2h2]n. the name refers to its conceptual construction from polymerization of acetylene to give a chain with repeating olefin groups. this compound is conceptually important, as the discovery of polyacetylene and its high conductivity upon dopi...
wikipedia
6c413b363178d4bb67fc8890c36e3d04a109c6ff
polyacetylene has no commercial applications, although the discovery
polyacetylene has no commercial applications, although the discovery of polyacetylene as a conductive organic polymer led to many developments in materials science. conducting polymers are of interest for solution-processing for film-forming conductive polymers. therefore, attention has shifted to other conductive poly...
wikipedia
fe3ebd4486fdf4ad675a84956bd6ed09bf1b9a7a
for applications, polyacetylenes suffer from many drawbacks. they
for applications, polyacetylenes suffer from many drawbacks. they are insoluble in solvents, making it essentially impossible to process the material. while both cis and trans -polyacetylene show high thermal stability, exposure to air causes a large decrease in the flexibility and conductivity. when polyacetylene is e...
wikipedia
e2521777022e503d80644ec56b0e1414d8f9bc48
the synthesis and processing of polyacetylene films affects
the synthesis and processing of polyacetylene films affects the properties. increasing the catalyst ratio creates thicker films with a greater draw ratio, allowing them to be stretched further. lower catalyst loadings leads to the formation of dark red gels, which can be converted to films by cutting and pressing betwe...
wikipedia
d2394b9de00666e64b147257ec2b7311853d405c
the structure of polyacetylene films have been examined
the structure of polyacetylene films have been examined by both infrared spectroscopy and raman spectroscopy, and found that the structure depends on synthetic conditions. when the synthesis is performed below −78 °c, the cis form predominates, while above 150 °c the trans form is favored. at room temperature, the poly...
wikipedia
70634be9217f70e88eb1c23379a9f07b5f58ab8c
the conductivity of polyacetylene depends on structure and
the conductivity of polyacetylene depends on structure and doping. undoped trans -polyacetylene films have a conductivity of 4.4×10 Ω cm, while cis -polyacetylene has a lower conductivity of 1.7×10 Ω cm. doping with bromine causes an increase in conductivity to 0.5 Ω cm, while a higher conductivity of 38 Ω cm is obtain...
wikipedia
c3d841801d7def1a116089eeb6f644261c851f58
electron-donating (n-type) dopants can also be used to
electron-donating (n-type) dopants can also be used to create conductive polyacetylene. n-type dopants for polyacetylene include lithium, sodium, and potassium. as with p-type dopants, charge-transfer complexes are created, where the polymer backbone is anionic and the donor is cationic. the increase in conductivity up...
wikipedia
d6d0eb8135bdc7b1dc729c045a7172c7b0fa3fb5
when polyacetylene films are exposed to vapors of
when polyacetylene films are exposed to vapors of electron-accepting compounds (p-type dopants), the electrical conductivity of the material increases by orders of magnitude over the undoped material. p-type dopants include br, i, cl, and asf. these dopants act by abstracting an electron from the polymer chain. the con...
wikipedia
b82d7a05ffcbd74d23bfa403fab1483221114473
more efficient methos for synthesizing long polyacetylene chains
more efficient methos for synthesizing long polyacetylene chains exist and include the durham precursor route in which precusor polymers are prepared by ring-opening metathesis polymerization, and a subsequent heat-induced reverse diels–alder reaction yields the final polymer, as well as volatile side products.
wikipedia
9d846d6d2defb493a9e822fa592b77008be3bbc1
polyacetylene can also be synthesized from other polymers.
polyacetylene can also be synthesized from other polymers. this method enables modification and processing of the polymer before conversion into the highly insoluble polyacetylene. short, irregular segments of polyacetylene can be obtained by dehydrohalogenation of poly(vinyl chloride):
wikipedia
bdc53872c61adf7abb21d976e86a21c49f8325d5
polyacetylene can be synthesized by ring-opening metathesis polymerisation
polyacetylene can be synthesized by ring-opening metathesis polymerisation (romp) from cyclooctatetraene, a material easier to handle than the acetylene monomer. this synthetic route also provides a facile method for adding solubilizing groups to the polymer while maintaining the conjugation. robert grubbs and coworker...
wikipedia
62dbf9efc63f22b4ad13205a8d711d471d9f6eff
polyacetylene can also be produced by radiation polymerization
polyacetylene can also be produced by radiation polymerization of acetylene. glow-discharge radiation, gamma radiation, and ultraviolet irradiation have been used. these methods avoid the use of catalysts and solvent, but require low temperatures to produce regular polymers. gas-phase polymerization typically produces ...
wikipedia
63bbbdb9fd18e84d6fe15165e3b654cfaebe83d8
by varying the apparatus and catalyst loading, shirakawa
by varying the apparatus and catalyst loading, shirakawa and coworkers were able to synthesize polyacetylene as thin films, rather than insoluble black powders. they obtained these films by coating the walls of a reaction flask under inert conditions with a solution of the ziegler–natta catalyst and adding gaseous acet...
wikipedia
7e5ded58114be10d8ab352a05f0e8937a0d7fea9
a variety of methods have been developed to
a variety of methods have been developed to synthesize polyacetylene. one of the most common methods is via passing acetylene gas over a ziegler–natta catalyst, such as ti(o i pr) / al(c h). this method allows control over the structure and properties of the final polymer by varying temperature and catalyst loading. me...
wikipedia
2b585a81bf74923c2bd4ae66ae6ede96c378cad1
to account for such an increase in conductivity
to account for such an increase in conductivity in polyacetylene, j. r. schrieffer and heeger considered the existence of topologically protected solitonic defects, their model is now known as the su–schrieffer–heeger model, which has served as model in other contexts to understand topological insulators.
wikipedia
cb97987742cf92be1e3d54e346c3c0193b2dd617
upon doping polyacetylene with i, the conductivity increased
upon doping polyacetylene with i, the conductivity increased seven orders of magnitude. similar results were achieved using cl and br. these materials exhibited the largest room temperature conductivity observed for a covalent organic polymer, and this seminal report was key in furthering the development of organic con...
wikipedia
68380c9207eda67f3dc19ddb5e0bb27a90fa5ef6
the next major development of polyacetylene polymerization was
the next major development of polyacetylene polymerization was made by hideki shirakawa ’s group who were able to prepare silvery films of polyacetylene. they discovered that the polymerization of polyacetylene could be achieved at the surface of a concentrated solution of the catalyst system of et al and ti(obu) in an...
wikipedia
f64e69f9a1e4c1df6a46c933db2dfe9b2be4c5ee
one of the earliest reported acetylene polymers was
one of the earliest reported acetylene polymers was named cuprene. its highly cross-linked nature led to no further studies in the field for quite some time. linear polyacetylene was first prepared by giulio natta in 1958. the resulting polyacetylene was linear, of high molecular weight, displayed high crystallinity, a...
wikipedia
a0263e3494ddab4308bad92b02309dc8f94c63dc
polyacetylene consists of a long chain of carbon
polyacetylene consists of a long chain of carbon atoms with alternating single and double bonds between them, each with one hydrogen atom. the double bonds can have either cis or trans geometry. the controlled synthesis of each isomer of the polymer, cis -polyacetylene or trans -polyacetylene, can be achieved by changi...
wikipedia
76966560fd0cafd95413c9b327854b674c0d4acb
compounds called polyacetylenes also occur in nature, although
compounds called polyacetylenes also occur in nature, although in this context the term refers to polyynes, compounds containing multiple acetylene groups ("poly" meaning many), rather than to chains of olefin groups ("poly" meaning polymerization of).
wikipedia
59b52e5dc286d1def75c7aabdb1ab831fd8e768b
polyacetylene (iupac name: polyethyne) usually refers to an
polyacetylene (iupac name: polyethyne) usually refers to an organic polymer with the repeating unit. the name refers to its conceptual construction from polymerization of acetylene to give a chain with repeating olefin groups. this compound is conceptually important, as the discovery of polyacetylene and its high condu...
wikipedia
146e5816f4833a340ad806b7948903ee5ca8eb2e
houman owhadi is a professor of applied and
houman owhadi is a professor of applied and computational mathematics and control and dynamical systems in the computing and mathematical sciences department at the california institute of technology. he is known for his work in statistical numerical approximation, kernel learning, and uncertainty quantification.
wikipedia
ecf9468ad24ddfca632adc78bd1333a335fd402b
owhadi won the epfl doctorate award for his
owhadi won the epfl doctorate award for his thesis in 2001. he was an invited lecturer at the siam conference on computational science and engineering in 2015 and a plenary speaker at the xvi international conference on hyperbolic problems. in 2019, he received the siam germund dahlquist prize. he was elected a siam fe...
wikipedia
9f2a8d6b63a82ae1779a318951a48c0649362eda
owhadi studied at the École polytechnique where he
owhadi studied at the École polytechnique where he received a m.s. in mathematics and physics in 1994 and was a civil servant in the corps des ponts in 1997. he received his ph.d. in mathematics from the École polytechnique fédérale de lausanne in 2001, studying under gérard ben arous. he was a cnrs research fellow bet...
wikipedia
146e5816f4833a340ad806b7948903ee5ca8eb2e
houman owhadi is a professor of applied and
houman owhadi is a professor of applied and computational mathematics and control and dynamical systems in the computing and mathematical sciences department at the california institute of technology. he is known for his work in statistical numerical approximation, kernel learning, and uncertainty quantification.
wikipedia
5534aa3ba8226b1079e9d9f41d9a06ed2d3d982f
buellia stellulata, an epilithic lichen, thrives on siliceous
buellia stellulata, an epilithic lichen, thrives on siliceous rock surfaces (typically hcl-) and is commonly found in coastal regions. however, its habitat is not restricted solely to seashore environments.
wikipedia
06008b192b089d11940882c6f2211f1d0d7c5c13
the lichen contains the secondary metabolites atranorin, 2'-o-methylperlatolic
the lichen contains the secondary metabolites atranorin, 2'-o-methylperlatolic acid, and confluentic acid. spot tests are k+ yellow (sometimes weak), p- or + faintly yellow, c-, kc-, and ck-. uv fluorescence is -(dark).
wikipedia
7a71a9d6e680e32117fbc54386b1f668a5663557
the asci are clavate, bacidia -type, and 8-spored.
the asci are clavate, bacidia -type, and 8-spored. the ascospores soon become brown, 1-septate, oblong to ellipsoid, usually not constricted, with obtuse ends, and not curved, measuring (8-)8.7--11.1(-13) x (4.5-)4.8--6.1(-7) μm. the proper septum is narrow and does not thicken during spore ontogeny (buellia-type). the...
wikipedia
c179b7aa348f49e2bceb2c34023f810708f86b62
the apothecia exhibit a lecideine structure, with a
the apothecia exhibit a lecideine structure, with a diameter ranging from (0.2-)0.3-0.4(-0.5) mm. they are typically immersed to adnate, occasionally found in a sessile form. the margin may appear black or masked by grayish remnants of necrotic thalline material, forming a thin and usually persistent boundary, occasion...
wikipedia
18c7a5bd84952599629db9a1c19a29b094db16fb
the thallus is crustose, areolate, and thin to
the thallus is crustose, areolate, and thin to moderately thickened, often forming a continuous layer. the prothallus is conspicuous and black, strongly developed in most specimens, growing between the areoles to form a hypothallus. the thallus surface is usually white to whitish gray, rarely dark gray, and can be dull...
wikipedia
6d7909a80ff101ddb7409c34890dfd11c6a73c9a
verstraete and verstraeten are dutch language toponymic surnames.
verstraete and verstraeten are dutch language toponymic surnames. the names are contractions of van der straate(n), meaning "from the street". "verstraete is mostly limited to west flanders while "verstraeten" is mostly limited to east flanders. notable people with the surname include: birger verstraete, belgian footba...
wikipedia
25e87fc05a6d5c7ba4b5ddd35bd109decae5e4f1
verstraete and verstraeten are dutch language toponymic surnames.
verstraete and verstraeten are dutch language toponymic surnames. the names are contractions of van der straate(n), meaning "from the street". "verstraete (6,633 people in belgium in 2007) is mostly limited to west flanders while "verstraeten" (5,511 people) is mostly limited to east flanders. notable people with the s...
wikipedia
7ab9606758c232fa82a37e812c241f013e765c16
eugene daniel berce was an american basketball player.
eugene daniel berce was an american basketball player. he played collegiately for the cornell big red and what are now the marquette golden eagles. he was selected by the new york knicks in the 1948 baa draft. he played for the tri-cities blackhawks (1949–50) in the nba for 3 games. he was the first marquette player to...
wikipedia
4959f64c248aa6f265e99573a282d72fcd179811
he was selected by the new york knicks
he was selected by the new york knicks in the 1948 baa draft. he played for the tri-cities blackhawks (1949–50) in the nba for 3 games. he was the first marquette player to score 1,000 career points, and is in the marquette hall of fame.
wikipedia
bb64fb5723c4871d1904eb3cfb3c092aea81992e
eugene daniel berce (november 22, 1926 – november
eugene daniel berce (november 22, 1926 – november 17, 2018) was an american basketball player. he played collegiately for the cornell big red and what are now the marquette golden eagles.
wikipedia