populations disperse after the breeding season .

this large stork has a massive wedge-shaped bill , a bare head and a distinctive neck pouch .

during the day , they soar in thermals along with vultures with whom they share the habit of scavenging .

they feed mainly on carrion and offal ; however , they are opportunistic and will sometimes prey on vertebrates .

the english name is derived from their stiff " military " gait when walking on the ground .

large numbers once lived in asia , but have declined greatly , possibly due to improved sanitation , to the point of being endangered .

the total population in 2008 was estimated at around a thousand individuals .

in the 19th century , they were especially common in the city of calcutta , where they were referred to as the " calcutta adjutant " .

known locally as hargila ( derived from the bengali words for " bone-swallower " ) and considered to be unclean birds , they were largely left undisturbed but sometimes hunted for the use of their meat in folk medicine .

valued as scavengers , they were once used in the logo of the calcutta municipal corporation .

greater adjutant

purnima devi barman explains the religious importance of the greater adjutant stork in a temple courtyard .
the greater adjutant is a huge stork named for its slow , measured gait , which resembles that of a military adjutant , or officer .
the greater adjutant is found only in two small , separate breeding populations in india and cambodia .
a conservation brigade of 70 villagers has created a safe haven for the endangered greater adjutant stork .
greater adjutant storks feeding on garbage dumping site in boragaon . . . . . purnima devi barman . .
the other 400 or so greater adjutant storks are found in the eastern indian state of bihar and in cambodia .
such accomplishments have encouraged the brigade to expand their protections to other greater adjutant nesting colonies in the brahmaputra valley .
the diet of the greater adjutant consists of a range of animal species , and it will even take injured ducks .
greater adjutant storks stand near a garbage dump on the outskirts of gauhati , india , on june 5 , 2012 .
greater adjutant storks feeding on garbage dumping site in boragaon . . . . . purnima devi barman . . - youtube
a teacher of sankardev sishu niketan school draws a greater adjutant stork on a blackboard at dadara village , west of guwahati .
the greater adjutant stork is one of the most endangered bird species widely distributed in the plains of the brahmaputra valley of assam . the present global population of the greater adjutant stork is about 1 , 500 — around 900 of them are in assam .
although the longest lifespan of a captive greater adjutant was 43 years , the longevity of these birds in the wild remains unknown .
the greater adjutant in assam takes to roosting in tall trees , a majority of which is now in privately - owned lands .
the greater adjutant was formerly found in south and southeast asia , but there are now just two small and separate breeding populations ; one in assam , india and one in cambodia . a migratory bird , the greater adjutant also visits viet nam , thailand and burma when not breeding
the greater adjutant retracts its neck in flight , probably due to the heavy bill . the large wings allow the bird to soar easily .
young boys carry carcasses of greater adjutant storks , which have either succumbed to the poison laced on the garbage or plastic mixed with waste .
a greater adjutant scans a lily - filled pond for fishes . the bird ' s wetland habitat is slowly being encroached upon by construction sites .
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the greater adjutant was formerly found in south and southeast asia , but there are now just two small and separate breeding populations ; one in assam , india and one in cambodia . a migratory bird , the greater adjutant also visits viet nam , thailand and burma when not breeding ( 3 ) .
in january more than two dozen greater adjutant storks were found dead in a neighbourhood near guwahati . forensic testing is being done to learn the cause .
choudhury , a . 2008 . counting large gatherings of globally threatened greater adjutant leptoptilos dubius . indian birds 4 ( 4 ) : 133 - 135 .
the greater adjutant is the most endangered stork of the world . the iucn , international wetland research bureau ( iwrb ) specialist group on stork , ibis and spoonbill ( sis ) and the international council of bird preservation ( icbp ) have all declared the greater adjutant stork as first priority species for conservation .
rahmani , a . , g . narayan , l . rosalin . 1990 . status of the greater adjutant ( leptoptilos dubius ) in the indian subcontinent .
goswami , s . k . ; patar , p . j . 2007 . fall in the number of greater adjutant nests in nagaon , assam , india .
in this june 5 , 2012 photo , a greater adjutant stork flies by its fellow birds near deepor beel wildlife sanctuary , on the outskirts of gauhati in assam .
singha , h . , a . rahmani , m . coulter , s . javed . 2002 . nesting ecology of the greater adjutant stork in assam , india .
the greater adjutant in non - breeding plumage has bluish - grey upperparts contrasting with pale grey greater coverts and tertials . the tail is dark grey . on the underparts , body and wing - coverts are whitish . the undertail feathers are blackish .
assam has about two - thirds of the greater adjutant stork in the world , largely in three villages just northwest of state capital guwahati . photos : anupam nath / ap
the greater adjutant ( leptoptilos dubius ) is a member of the stork family , ciconiidae . its genus includes the lesser adjutant of asia and the marabou stork of africa . once found widely across southern asia , mainly in india but extending east to borneo , the greater adjutant is now restricted to a much smaller range with only two small breeding populations ; one in india with the largest colony in assam and the other in cambodia .
the greater adjutant ( leptoptilos dubius ) is a member of the stork family , ciconiidae . its genus includes the lesser adjutant of asia and the marabou stork of africa . once found widely across southern asia , mainly in india but extending east to borneo , the greater adjutant is now restricted to a much smaller range with only two small breeding populations ; one in india with the largest colony in assam and the other in cambodia .
the greater adjutant is classified as endangered ( en ) on the iucn red list ( 1 ) and is listed under schedule iv of the wildlife act 1972 ( 3 ) .
greater adjutants are important scavengers of large carrion and likely contribute to sanitation and disease control in the environment . like many birds , greater adjutants are hosts to avian lice including
september at dadara . when the village women group was offering prayers to god for the welfare of greater adjutant and for a successful breeding season ahead , they were stunned and speechless .
range : the greater adjutant is found in e nepal , n india and n bangladesh and indochina ( mainly in cambodia ) . it breeds only in assam valley , bihar and cambodia .
introduction : the greater adjutant is a huge , bulky stork of ne india and se asia . like the lesser adjutant and the marabou stork , it has a huge , thick bill and bare skin on the head . the large wingspan allows the bird to soar easily , but it flies with retracted neck due to the heavy bill . the name “adjutant” is derived from it stiff gait while walking on the ground . the greater adjutant has very small population that is declining rapidly . this species is threatened by habitat destruction , pollution and persecution . it is currently classified as endangered .
singha , h . , a . rahmani , m . coulter , s . javed . 2003 . surveys for greater adjutant leptoptilos dubius in the brahmaputra valley , assam , india during 1994–1996 .
greater adjutant stork , the world’s most endangered of the stork species , has found a secure home to breed in two nondescript villages of assam’s kamrup district , heralding a new chapter in its conservation .
tree of life web project . 2008 . leptoptilos dubius . greater adjutant . version 27 june 2008 ( temporary ) . available at : urltoken . ( accessed : 01 / 08 / 2013 ) .
in a few months , the greater adjutant stork—called hargilla , which means
swallower of bones
in sanskrit—will descend on this hamlet , situated in assam ' s brahmaputra valley , to breed in large numbers .
a group of women in the brahmaputra river valley are leading a community - based effort to protect the greater adjutant ( a stork also known as the hargilla ) , which once ranged from pakistan to cambodia .
calls and songs : the greater adjutant is often silent away from the nest . like other ciconiidae , it performs bill - clattering during the displays , but also produces low grunting , croaking and roaring sounds .
a vast expanse of stinking garbage has become one of the favoured feeding grounds of the rare greater adjutant stork . one shudders to think of the toxic substances that these scavengers must be ingesting along with their food .
a huge stork species , the greater adjutant ( leptoptilos dubius ) has a naked pink head , a very thick yellow bill and a low - hanging neck pouch . the neck ruff is white and , other than the pale grey leading edge of each wing , the rest of the greater adjutant’s body is dark grey . juveniles have a narrower bill , thicker down on the head and neck and entirely dark wings ( 2 ) .
barman , p . d . and sharma , d . k . in press . conservation of endangered greater adjutant stork in assam , india . wildlife institute of india envis : 192 - 199 ( in press ) .
sometimes the women even play the part of greater adjutants themselves , donning masks in street - corner plays .
earlier , widely distributed throughout northern and eastern india and many countries of south and south - east asia , the greater adjutant stork is currently distributed only in assam and bihar in india and a few other locations in cambodia .
the greater adjutant ( leptoptilos dubius ) is the largest stork species in the world , reaching 1 . 5 meters in height , and is listed on the international union for conservation of nature ( iucn ) red list as endangered .
behaviour in the wild : the greater adjutant feeds mainly at carcasses and often scavenges through garbage disposal areas . the digestive system of these large storks allows them to eat and swallow bones , giving them the name “hargila” ( bone swallower ) .
the greater adjutant in breeding plumage has blackish face and forehead , whereas head and neck are redder . we can see an inflated hanging gular pouch and a reddish bulge at base of the rear neck . the upperparts are paler bluish - grey with silvery greater coverts and tertials . the neck pouch becomes bright saffron - yellow whereas the upper tibia is reddish .
“we had to involve the locals because the bird nests on trees owned by individual households . the future of the greater adjutant stork depends on individual tree owners who used to fell trees earlier to get rid of the nests , ” barman said .
singha , h . ; rahmani , a . r . 2006 . ecology , population and conservation of greater adjutant leptoptilos dubius in assam , india . journal of the bombay natural history society 103 ( 2 - 3 ) : 264 - 269 .
the greater adjutant usually disperses after breeding and it is locally migratory and subject to wandering movements . it was formerly more widely distributed in india and bangladesh . it is a non - breeding visitor in nepal . but current / former status is unclear .
phnom penh , july 27 ( xinhua ) - - globally endangered greater adjutant chicks have successfully fledged from 175 nests in the prek toal ramsar site in northwest cambodia ' s battambang province and disbursed across the country , a conservationist group said on thursday .
the lesser adjutant ( leptoptilos javanicus ) is a large wading bird in the stork family ciconiidae . like other members of its genus , it has a bare neck and head . it is however more closely associated with wetland habitats where it is solitary and is less likely to scavenge than the related greater adjutant . it is a widespread species found from india through southeast asia to java .
singha , h . , rahmani , a . r . , couller , m . c . and javed , s . ( 2002 ) nesting ecology of the greater adjutant stork in assam , india . waterbirds , 25 ( 2 ) : 214 - 220 .
but thanks to the efforts of the hargilla army , a conservation brigade of 70 local women , the region is now
the biggest greater adjutant nesting colony in the world ,
says purnima devi barman , a wildlife biologist with aaranyak , a conservation nonprofit in assam .
mishra , a . ; mandal , j . n . 2009 . discovery of a breeding ground of the greater adjutant leptoptilos dubius and their conservation in the floodlands of bihar , india . journal of the bombay natural history society 106 ( 2 ) : 190 - 197 .
andheria , a . ( 2003 ) .
first sighting of lesser adjutant - stork leptoptilos javanicus from sanjay gandhi national park , mumbai
.
the greater adjutant stork is the most threatened stork in the world and its population is decreasing . many historic breeding colonies of this colonial nesting bird are missing now and the bird is probably facing extinction threat . brahmaputra valley in assam is considered as the last stronghold for endangered greater adjutant and supports more than 90 % of its global population . it is now utmost important to know the current population scenario of the bird to initiate conservation measures and habitat recovery plans . the present project is aimed to initiate greater adjutant conservation programmes across the entire distribution range in assam and , based on results and recommendations of a previous project , the team will involve communities and help policy makers to improve and secure its conservation status . the current project will concentrate on the entire distribution range of greater adjutant in brahmaputra valley of assam , india . community based organisations will help to collect information on the species , spread conservation awareness messages to the masses and for save nest fall chicks in the nesting colony areas . a long term conservation action plan will be prepared and published to support existing government conservation initiatives so that the population decline can be stabilised .
sayam u . chowdury & msh sourav ( 2012 ) .
discovery of a lesser adjutant leptoptilos javanicus breeding colony in bangladesh journal = birdingasia
.
however , the greater adjutant also forages in shallow , drying pools where it searches for insects , frogs , large fish , crustaceans , and sometimes injured ducks or waders . it forages by using a tactile technique , holding its beak open underwater and waiting for passing prey between the open mandibles .
but fast - vanishing wetlands in and around the city has now become a major threat for the survival of the stork . guwahati has the largest concentration of the endangered greater adjutant storks in the world , and forage for food at the city’s main dumping ground near the deepor beel wildlife sanctuary .
little is known about the territory size for greater adjutants . male greater adjutants will advertise their claim on a suitable nesting branch with beak clattering . they are known to build nests relatively close to one another , so breeding territory size is likely small and limited to a nesting branch .
singha , h . ; rahmani , a . r . ; coulter , m . c . ; javed , s . 2003 . breeding behaviour of the greater adjutant - stork leptoptilos dubius in assam , india . journal of the bombay natural history society 100 ( 1 ) : 9 - 26 .
prek toal is home to the world ' s second largest greater adjutant breeding colony after that in assam , india , the release said , adding that the site is the premier freshwater wetland area on the tonle sap great lake , and is well known for its incredible biological , social and economic resources .
huge , dark stork with very thick bill and pendulous neck - pouch . pinkish naked head , white neck - ruff . pale grey greater coverts and tertials contrasting with otherwise dark upperwing . underwing - coverts paler than flight feathers . juvenile has narrower bill than adult , denser head and neck - down and , initially , all dark wings . similar spp . lesser adjutant l . javanicus is smaller , lacks neck pouch , has black greater coverts and tertials
the national green tribunal has issued a notice to the assam government on the mass death of 26 greater adjutant storks at a garbage dump adjoining deepor beel , near guwahati . there are two ironies here : the greater adjutant , a towering , endangered stork standing over five feet tall , has been routinely documented to be subsisting almost entirely on trash in guwahati . this is a tragicomic adaptation for a hunting and scavenging bird that otherwise eats fish , rats and snakes . the second irony is that nearly all of guwahati’s waste is illegally going into deepor beel , a wetland that is notified as a sanctuary and internationally considered to be important .
tree and animal species are symbols of gods and goddesses in indian culture making ritual beliefs an important consideration as we seek to protect our rich biodiversity . indeed , i have found ritual beliefs to be a major tool for conservation awareness during my entire journey with the greater adjutant stork in a small assamese village called dadara .
protection / threats / status : the greater adjutant is threatened by habitat loss , both feeding and nesting habitats , through drainage of wetlands , disturbance , pollution and persecution , owing to its pest status . reduction of open rubbish dumps with carcasses and foodstuffs is a significant threat for these scavengers . the population has declined catastrophically with a recent estimation of 800 / 1 , 200 mature individuals , equating to 1 , 200 / 1 , 800 individuals . this population is rapidly decreasing . the greater adjutant is currently classified as endangered , in spite of legal protection within the range , and its presence in some protected national parks in assam , india .
dhritiman das ' s photo of storks foraging in a dump was joint overall runner - up . the greater adjutant stork is the world ' s most endangered stork . the world ' s largest concentration of the birds is found in the urban garbage dumps of guwahati city in india , because of the destruction of surrounding wetlands .
in their native range , where they are primarily scavengers of large carrion , greater adjutants are known by the name
hargila ,
meaning bone swallower . they were once prevalent in calcutta , where their tendency to consume human corpses left to rot in the streets was valued . one record indicates that a single greater adjutant effortlessly swallowed two buffalo vertebrae , measuring approximately 30 cm in length , in less than five minutes . greater adjutants are most commonly found scavenging in mixed flocks near human garbage dumps or large carcasses . they can also be seen foraging independently near drying pools where they hunt insects , frogs , large fish , crustaceans and injured waterfowl . when foraging , greater adjutants use a method of tactile foraging where they hold their beaks open underwater and patiently wait for a prey item to swim between the open mandibles .
the greater adjutant feeds by sweeping its bill under the surface of the water , or by probing into the substrate . it will consume carrion , fish , frogs , reptiles , crustaceans , large insects and even injured ducks . it is also known to feed in human refuse dumps , where it will take food from other scavengers , including vultures
whilst legally protected in india , bangladesh , burma , thailand , cambodia and laos , and occurring in three national parks in assam , india , the greater adjutant still suffers from hunting and egg collection due to poor enforcement of protection . there has been some successful control of egg and chick collection following efforts by the wildlife protection office staff in cambodia , which resulted in higher numbers of storks the following year . it has been proposed that the greater adjutant should be moved from schedule iv to schedule i of the indian wildlife act of 1972 to give it greater priority . effective land management is necessary for the survival of this species , particularly the control of pesticide use around feeding areas and the protection of feeding areas and nesting sites found outside protected areas . further research into the seasonal movements of these birds and the threats that face them is also important ( 3 ) .
the greater adjutant stork breeds singly , semi - colonially or colonially in arboreal sites that have been in use for many years . characteristically , they to place their nest on very tall trees — most of them are located now on privately - owned land . the nests are usually located within within 300 metres of human habitation in densely - populated urban areas .
135 - 150 numbers of greater adjutants are found evryday in boragaon garbage dumping site near deepar beel ramsar site ( guwahati city ) , assam . photopurnima devi barman . .
gathering in compact colonies at the start of the dry season in october , the greater adjutant nests on large , widely branched trees with few leaves ( 4 ) . it constructs a large platform of sticks with an outer layer of bamboo stems and lines this with leaves . two to four eggs are laid between november and january . after 28 to 30 days , the eggs hatch , and the nestlings are cared for until april . at the start of the wet season , the greater adjutants migrate to northern india ( 3 ) .
the greater adjutant feeds by sweeping its bill under the surface of the water , or by probing into the substrate . it will consume carrion , fish , frogs , reptiles , crustaceans , large insects and even injured ducks . it is also known to feed in human refuse dumps , where it will take food from other scavengers , including vultures ( 3 ) .
elliott , a . and kirwan , g . m . 2016 . greater adjutant ( leptoptilos dubius ) . in : del hoyo , j . , elliott , a . , sargatal , j . , christie , d . a . and de juana , e . ( eds ) , handbook of the birds of the world alive , lynx edicions , barcelona .
greater adjutants are valuable scavengers of discarded human waste , including unburied corpses as well as other large carrion . this service may have a role in preventing the spread of disease .
guwahati : the greater adjutant stork used to be an object of revulsion in northeast india . it’s not a pretty bird , with its large , dull - orange bill and gray , black and white plumage . a carnivore and scavenger , it left bits of dead animals in its nests . people thought it brought bad luck , so they destroyed nests and sometimes poisoned the birds .
maust , m . , clum , n . and sheppard , c . ( 2007 ) .
ontogeny of chick behavior : a tool for monitoring the growth and development of lesser adjutant storks
.
dadara and two nearby villages , pasariya , and singimari , are flanked by food - rich wetlands and brimming with tall trees perfect for nesting . the region has become a major stronghold for this homely creature : due mostly to deforestation and widespread development of wetlands , only between 800 and 1 , 200 greater adjutant storks remain in india and cambodia , according to the international union for conservation of nature .
while greater adjutants pose no threat to humans they are often looked upon with disgust because of their general appearance , habit of defecating on their own legs , as well as diet of carrion .
assam is the international stronghold of the greater adjutant stork , carnivore and scavenger . according to estimates from the international union for conservation of nature and natural resources only 1 , 200 of the large storks survive . assam has about two - thirds of them , largely in three villages just northwest of state capital guwahati . but the locals here felt that it brought bad luck , so they destroyed nests and sometimes poisoned the birds .
elliott , a . & kirwan , g . m . ( 2018 ) . greater adjutant ( leptoptilos dubius ) . in : del hoyo , j . , elliott , a . , sargatal , j . , christie , d . a . & de juana , e . ( eds . ) . handbook of the birds of the world alive . lynx edicions , barcelona . ( retrieved from urltoken on 9 july 2018 ) .
, which may have a negative impact upon the species in the future . young birds may also become entangled in fishing nets and the species may suffer from the disturbance of arboreal animals , competition for nesting habitat from the lesser adjutant
but , the fortunes of the species changed as the local women took it upon themselves to save this bird . the women known as the ‘hargila’ army , for the bird’s name in the assamese language , sing hymns and weave scarves and other items on handlooms with motifs of the bird to create awareness about the need to protect the species . the other 400 or so greater adjutant storks are found in the eastern indian state of bihar and in cambodia .
reproduction of this species : the breeding season takes place between october - december and february in burma , cambodia and india . the greater adjutant nests in colonies , but now more restricted to small colonies of less than 30 pairs and scattered solitary pairs . it shares these colonies with other species such as the lesser adjutant , the asian openbill and some pelicans . the colonies are established in large trees with sparse foliage , in order to make easier both landing and take - off for these large birds . the stick nest is a large , bulky structure with a deep cup lined with fresh vegetation , placed in tree between 12 and 30 metres above the ground , and sometimes on rock ledges .
habitat : the greater adjutant frequents freshwater marshes and pools , freshwater swamp forest and sometimes ricefields and open areas . the species occurs in lowlands , but it may occasionally reach 1500 metres of elevation in nepal , in himalayan foothills . at other times , the birds can be seen foraging at urban disposal sites . they often gather around carcasses and at rubbish dumps in open fields but also near towns . it can be seen perched on houses and wandering about by markets for food .
many consider greater adjutants to be the most endangered stork in the world . captive breeding programs have failed thus far , but efforts to protect natural habitats are active . unfortunately , their tendency to nest near human settlements may prove fatal .
i am proud of working with my team to conserve this rare bird and am happy to see greater adjutants and other important waterbirds living and breeding safely here ,
said chhan chhoum , former egg collector and a nest protector .
in the early part of the 20th century , the population size of greater adjutants is said to have numbered in the millions . they were common in northern india , bangladesh , nepal and southern vietnam . beginning in the mid 1980 ' s the population began to decline heavily . today an estimated 1 , 000 birds remain and likely breed only in the politically unstable assam state of northern india . populations are still declining and the iucn red list lists greater adjutants as endangered .
both male and female greater adjutants participate in nest building . after the eggs are laid , both parents also incubate the clutch for 28 to 30 . the altricial chicks are cared for by both parents until they fledge at 5 months old .
greater adjutants lack vocal muscles so they rely on unique behaviors and tactile forms of communication to interact with each other . males often utilize beak clattering to advertise their territory and ward off other males . males attract mates by presenting them with fresh twigs and later holding their beaks close to the female . breeding pairs also perform head bobbing rituals that likely reinforce their pair - bond . like all birds , greater adjutants perceive their environments through visual , auditory , tactile , and chemical stimuli .
felling of large nesting trees , pollution of freshwater systems and a decline in the disposal of human corpses in public trash dumps are all thought to contribute to the rapid loss of this species . in assam , recent reports of disease in this species also seems to be a contributing factor in its decline . results of a survey of assam residents revealed that only 30 % of those polled knew greater adjutants are endangered . greater community awareness of this unique species may help in its recovery .
the greater adjutant stork ( hargila in assamese ) is a threatened bird and assam is considered its last global strong hold . hargila make their nesting colonies mainly in tall , privately owned trees . with about 500 birds in three villages , the area hosts the largest nesting colony of this species in the world . the global population of this bird is about 1 , 000 individuals . the key to the survival of this species is achieving the good wishes of the villagers towards this bird . this is our work .
the greater adjutant is monogamous , but the pair bond does not always last for life . it is colonial nester . the males advertise their territories by perching on the nesting branch while performing bill - clattering with the bill upwards . if some females perch close to the males , they present some twigs as courtship , but they also adopt ritualized postures , holding the huge bill close to a potential mate or hiding her head under the chin . both mates perform other displays together , especially up - down bobbing motions .
) are exceedingly rare in their range from northern india to indochina and may breed exclusively in the brahmaputra valley of assam . in the early part of the 20th century , large breeding populations of greater adjutants were common throughout northern india , bangladesh , nepal and southern vietnam .
greater adjutants are often seen foraging alone or in small groups . in general they are a non - migratory species but some make local movements to winter nesting sites . the name ' adjuntant ' comes from their distinctive , military - style gait . their large wingspans facilitate soaring and they are frequently found near thermals . due to their hot environments , greater adjutants defecate on their legs and the evaporation lowers body temperature ( also known as urohydrosis ) . as a result of this cooling mechanism , legs of these birds are often stained white with uric acid .
it is possible , however , that the pandemic’s close association with world war i may have caused this amnesia . while more people died from the pandemic than from world war i , the war had lasted longer than the pandemic and caused greater and more immediate changes in american society .
the juvenile has narrower bill than adults and the eyes are brownish - blue to bluish - brown . head and neck show denser hair - like feathering . the upperparts are duller . the wings are all - dark first , before to acquire a brown band across greater coverts and tertials .
singha , h . ; goswami , s . k . ; phukan , r . ; talukdar , b . k . 2006 . rehabilitation of captive - reared greater adjutants leptoptilos dubius in assam . journal of the bombay natural history society 103 ( 2 - 3 ) : 315 - 320 .
greater adjutants are large birds , ranging in height from 120 to 152 cm with an impressive 250 cm wingspan . a long , thick yellow bill precedes the sparsely feathered , yellow to pink head and neck . the head is typically dappled with dark scabs of dried blood and characterized by the presence of a pendulous , inflatable gular pouch . the legs are naturally dark in color but frequently appear ashen due to regular defecation on the legs . when in flight , greater adjutants are recognizable by their white underside feathers and tendency to retract their necks like a heron . a mixture of white and gray feathers , which appear darker during the non - breeding season , adorn the rest of the body . juvenile greater adjutants resemble adults , but have duller plumage and more feathers around the neck . the mass of these birds is unknown in the wild , but is estimated to be the heaviest of the storks .
dadara proved that community driven conservation is the key to protect wildlife . there were 15 nesting trees of greater adjutants in the village in 2008 when i started my work . last year we counted 171 nests . kudos to the tree owners that from 2010 , there was not a single tree cut down in the villages .
for instance , the presence of storks in garbage dumps in guwahati has come to be so accepted that the state government and civil society are using the dump as release sites for birds . the same dump is also the repository for biomedical waste , which veterinarians say could potentially kill any animal if it were to be ingested . in 2016 , a greater adjutant chick that had fallen out of its nest was nursed back to health . when deemed fit for release , it was let go in a garbage dump in boragoan area of the city , which in turn leads into deepor beel . while the chick would be surrounded by trash , there was also a colony of storks living in the area to keep it company .
scavenging in toxic environments is a harsh reality for birds . nonetheless , storks eating trash may not be a preferred choice . in assam , storks are also found in nagaon ( where they do not eat garbage ) . in bihar , greater adjutant storks have never been seen eating garbage . there are breeding populations of the species in kadwa kosi diara in the ganges and in khagaria . “this could possibly be because the garbage dumps here are smaller and the areas where the storks breed don’t have significant non - vegetarian demographics , ” says wildlife conservationist arvind mishra . “of course there is also the fact that there are natural wetlands for the storks to feed in . they eat snakes and rats in paddy fields , and fish from waterbodies . ”
145 - 150 cm . huge , dark stork with very thick bill and pendulous neck - pouch . pinkish naked head , white neck - ruff . pale grey greater coverts and tertials contrasting with otherwise dark upperwing . underwing - coverts paler than flight feathers . juvenile has narrower bill than adult , denser head and neck - down and , initially , all dark wings .
examinations had to be adapted to the limitations of time , place , and available equipment . ” when fitzsimons informed hillman later that new recruits were arriving at the hospital with tuberculosis , he responded almost plaintively . “i am working with the adjutant general to devise some method by which every volunteer for enlistment in the regular army will have a chest x - ray and serological test before acceptance . ” he asked for all available evidence of sick recruits , explaining that “data on regular army men of short service now in fitzsimons with tuberculosis will help me get the thing across . ” as the data and advice accumulated , in january 1942 , the adjutant general required that all voluntary applicants and reenlisting men be given chest x - rays . finally , on 15 march 1942 , mobilization regulations made chest x - rays mandatory in all induction physicals .
on average , the greater bamboo lemur consumes ten times the amount of cyanide that would be lethal to other mammals of its size . the toxin is found in the critically endangered lemur ' s main food source , madagascan giant bamboo ; how the animal safely swallows it is not yet understood . the judges highly commended this shot of a lemur munching on a toxic tidbit . ( photo : peggy boone )
a large stork with an upright stance , a bare head and neck without a pendant pouch , it has a length of 87–93 cm ( 34–37 in ) ( outstretched from bill - to - tail measurement ) , weighs from 4 to 5 . 71 kg ( 8 . 8 to 12 . 6 lb ) and stands about 110–120 cm ( 43–47 in ) tall . [ 2 ] [ 3 ] [ 4 ] the only confusable species is the greater adjutant , but this species is generally smaller and has a straight upper bill edge ( culmen ) , measuring 25 . 8–30 . 8 cm ( 10 . 2–12 . 1 in ) in length , with a paler base and appears slightly trimmer and less hunch - backed . the skullcap is paler and the upper plumage is uniformly dark , appearing almost all black . the nearly naked head and neck have a few scattered hair - like feathers . the upper shank or tibia is grey rather than pink , the tarsus measures 22 . 5–26 . 8 cm ( 8 . 9–10 . 6 in ) . the belly and undertail are white . juveniles are a duller version of the adult but have more feathers on the nape . [ 5 ] during the breeding season , the face is reddish and the neck is orange . the larger median wing coverts are tipped with copper spots and the inner secondary coverts and tertials have narrow white edging . the wing chord measures 57 . 5–66 cm ( 22 . 6–26 . 0 in ) in length . like others in the genus , they retract their necks in flight . in flight , the folded neck can appear like the pouch of the greater adjutant . [ 6 ] males and females appear similar in plumage but males tend to be larger and heavier billed . [ 4 ] [ 7 ]
greater adjutants nest in large , broad - limbed trees with sparse foliage . this choice of nesting tree is thought to facilitate landing and take - off for the large adult birds . nests are constructed out of sticks and several pairs will often occupy the same tree . while females lay 3 eggs per season , an average of 2 . 2 chicks per pair are fledged successfully each year . both parents participate in incubating eggs until they hatch after 28 to 30 days . chicks fledge at 5 months of age .
but the impact of garbage and toxins on species is still to be understood . traditionally , greater adjutants used to fly in the sky , alongside vultures , looking for food . as the vulture population crashed , ecologists have wondered what the fate of the storks would be . in guwahati’s huge mountains of garbage , the storks discovered feeding grounds – but it is certainly an uneasy truce . among bird species , scavengers are especially at risk of poisoning because a single infected carcass can affect many birds . scavenging birds tend to feed en masse .
the medical department of the united states army in the world war . communicable and other diseases . washington : u . s . government printing office , 1928 , vol . ix , pp . 171 - 202 . letter , the adjutant general , to commanding generals of all corps areas and departments , 25 oct . 1940 , subject : chest x - rays on induction examinations . m . r . no . 1 - 9 , standards of physical examination during mobilization , 31 aug . 1940 and 15 mar . 1942 long , e . r . : exclusion of tuberculosis . physical standards for induction and appointment . [ official record . ]
organophosphates were introduced around 1950 , as a replacement for the chlorinated hydrocarbons to which significant resistance had occurred ( shanahan and hart , 1966 ) . these are esters of phosphoric acid and have a wide range of activities against ticks at very low concentration in companion and livestock animals . however , their residual effectiveness is usually shorter than that of chlorinated hydrocarbons , and the risk of causing acute toxicity in livestock is greater ( drummond , 1983 ) . resistance in ticks was first recognized in 1963 and several tick species are now known to be resistant to organophosphorous acaricides ( wharton , 1967 ) .
the lesser adjutant tends to be widely dispersed and is very local . it is often found in large rivers and lakes inside well wooded regions . it is found in india , nepal , [ 8 ] sri lanka , bangladesh ( a colony with about 6 nests and 20 individuals was discovered near thakurgaon in 2011 . [ 9 ] ) , myanmar , thailand , vietnam , malaysia , laos , singapore , [ 10 ] indonesia and cambodia . the largest population is in india in the eastern states of assam , west bengal and bihar . it may occur as a vagrant on the southern edge of bhutan . [ 11 ] they are extremely rare in southern india . [ 12 ] [ 13 ]
other storks are known to be monogamous , but not always paired for life . it is thought that greater adjutants follow this mating system . great adjutants are colonial nesters and will build many nests in the canopy of a single tree . males claim suitable nesting branches and advertise their territory by perching on the branch with bills upward and exhibiting bill - clattering . when females perch nearby , males will present them with twigs as part of courtship . courtship rituals consist more of courtship postures , where males will hold their beaks close to potential mates or tuck the females heads under their chins . pairs also perform up - down bobbing motions together .
the lesser adjutant stalks around wetlands feeding mainly on fish , frogs , reptiles and large invertebrates . they rarely feed on carrion . they may also take small birds and rodents particularly during the breeding season . they are solitary except during the breeding season when they form loose colonies . [ 2 ] the breeding season is february to may in southern india and november to january in north - eastern india . [ 14 ] the nest is a large platform of sticks placed on a tall tree . the nest diameter is more than a metre and up to a metre deep . [ 2 ] the clutch consists of three to four eggs . [ 14 ] [ 15 ] they are silent but have been noted to clatter their bill , hiss and moan at the nest . [ 6 ]
most people imagine that the police are insensitive to wildlife conservation , but we know differently . the police are resource - rich in emergency situations and if they want to , they can be game changers for the conservation of greater adjutants . the kamrup district superintendent of police , partha sarathi mahanta , in particular , helped us in every possible way and made our mission his own . he alone released four rescued chicks that had been hand reared by a facility run by the wildlife trust of india . the released chicks were named monalisa , lulu , saru and rima ( after the tree owner’s daughters and wife ) and this simple gesture generated even more warmth and support for the birds . i still remember one bird whom we named christina , which attracted media .
the species breeds in the dry season ; birds congregate at the nesting areas from october onwards and lay eggs between november and january . the species breeds singly , semi - colonially or colonially in traditional arboreal sites which are sometimes used for many years , often in colonies mixed with other waterbirds , including lesser adjutant . characteristically , adjutants of both species tend to place their nest on very tall trees . of 278 clutches examined in assam , all contained 2 - 3 white eggs . similarly , at the sittang valley colony most clutches contained three eggs , while those at the needong hills comprised 3 - 4 eggs . the incubation period is 28 - 30 days . in assam , 61 . 3 % of eggs in 278 clutches produced fledglings . both sexes share nest building , incubation and feeding of the nestlings . adults wil bring water to juveniles on the nest , either to cool them down or for them to drink .
influenza has long been a global public health priority because of the threat of another global pandemic . although data are available for the annual burden of seasonal influenza in many developed countries , fewer disease burden data are available for low - income and tropical countries . in recent years , however , the surveillance systems created as part of national pandemic preparedness efforts have produced substantial data on the epidemiology and impact of influenza in countries where data were sparse . these data are leading to greater interest in seasonal influenza , including implementation of vaccination programs . however , a lack of quality data on severe influenza , nonrespiratory outcomes , and high - risk groups , as well as a need for better mathematical models and economic evaluations , are some of the major gaps that remain . these gaps are the focus of multilateral research and surveillance efforts that will strengthen global efforts in influenza control in the future .
2012 ) . in cambodia , the breeding colony at prek toal is a core area of the tonle sap biosphere reserve . greater adjutants historically bred at other sites on the tonle sap , but these colonies were abandoned by 2001 . conservation actions to reduce chick and egg collection and other forms of disturbance to the breeding colony at prek toal have been in place since the late 1990s , with permanent teams of protectors employed since 2001 . since 2001 , c . 95 % of waterbird egg and chick collection has been prevented at prek toal . it is included in waterbird conservation awareness material in laos and cambodia . in kamrup district , assam a successful community conservation programme ran from 2009 to 2014 and during this period there were no records of nesting trees being cut down and the number of successful nests grew from 65 in 2010 - 2011 to 148 in 2013 - 2014 ( barman and sharma in prep . ) .
the name of spanish flu came from the early affliction and large mortalities in spain ( bmj , 10 / 19 / 1918 ) where it allegedly killed 8 million in may ( bmj , 7 / 13 / 1918 ) . however , a first wave of influenza appeared early in the spring of 1918 in kansas and in military camps throughout the us . few noticed the epidemic in the midst of the war . wilson had just given his 14 point address . there was virtually no response or acknowledgment to the epidemics in march and april in the military camps . it was unfortunate that no steps were taken to prepare for the usual recrudescence of the virulent influenza strain in the winter . the lack of action was later criticized when the epidemic could not be ignored in the winter of 1918 ( bmj , 1918 ) . these first epidemics at training camps were a sign of what was coming in greater magnitude in the fall and winter of 1918 to the entire world .
endemic mycoses represent a growing public health challenge in north america . we describe the epidemiology of 1 , 392 microbiology laboratory–confirmed cases of blastomycosis , histoplasmosis , and coccidioidomycosis in ontario during 1990–2015 . blastomycosis was the most common infection ( 1 , 092 cases ; incidence of 0 . 41 cases / 100 , 000 population ) , followed by histoplasmosis ( 211 cases ) and coccidioidomycosis ( 89 cases ) . incidence of blastomycosis increased from 1995 to 2001 and has remained elevated , especially in the northwest region , incorporating several localized hotspots where disease incidence ( 10 . 9 cases / 100 , 000 population ) is 12 . 6 times greater than in any other region of the province . this retrospective study substantially increases the number of known endemic fungal infections reported in canada , confirms ontario as an important region of endemicity for blastomycosis and histoplasmosis , and provides an epidemiologic baseline for future disease surveillance . clinicians should include blastomycosis and histoplasmosis in the differential diagnosis of antibiotic - refractory pneumonia in patients traveling to or residing in ontario .
one year later , muraille et al . demonstrated the importance of the myd88 pathway in c57bl / 6 mice , a model of the dominant th1 response with a tendency to cure the cutaneous ulcers caused by leishmania . myd88 − / − mice had a greater number of cutaneous lesions than wild - type c57bl / 6 mice ( myd88 + / + ) . the number of lesions of the myd88 − / − mice was close to that of balb / c mice , which have a dominant th2 response and a tendency to have an increased number and severity of lesions ( 59 ) . increased levels of il - 4 and decreased levels of ifn - γ and il - 12 ( p40 ) were also demonstrated . a similar study was performed by debus et al . using c57bl / 6 mice ( myd88 − / − ) , and they obtained the same results . they therefore evaluated a group of mice with a monoclonal antibody against il - 4 , which enhanced the th1 response with higher ifn - γ levels ( 24 ) .


epermenia commonella is a moth in the epermeniidae family .

it was described by gaedike in 1968 .

it is found in australia , where it has been recorded from queensland .

epermenia commonella

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this adult moth has cream forewings , each with several bands of brown speckles .
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hyposmocoma tantala is a species of moth of the cosmopterigidae family .

it is known only from mount tantalus on oahu .

the length of the forewings is 5.5 millimetres ( 0.22 in ) for males and 6.2 millimetres ( 0.24 in ) for females .

the larval case is dark brown , smooth , 9 millimetres ( 0.35 in ) in length and 2 millimetres ( 0.079 in ) wide .

adults were reared from case-making larvae collected on bark of a damp dead tree covered partially with lichen .

hyposmocoma tantala

figures 7–10 . larval cases of some purse - cased hyposmocoma . 7 hyposmocoma ipohapuu sp . n . 8 hyposmocoma makawao sp . n . 9 hyposmocoma nebulifera 10 hyposmocoma tantala sp . n . scale bar = 1 mm .
using molecular and morphological data , kawahara and co - author daniel rubinoff of the university of hawaii named three new species that produce tubular purse cases : hyposmocoma ipohapuu from the big island , hyposmocoma makawao from makawao forest reserve in maui and hyposmocoma tantala from mount tantalus , oahu . the genus hyposmocoma includes about 350 described species and represents about 40 percent of all the moths and butterflies on the hawaiian islands .
the lepidopteran genus , hyposmocoma , contains over 300 species in the hawaiian islands . many species are only found on a single volcano or valley within an island . most members of the family cosmopterigidae , feed after burrowing into plant tissues . however , hyposmocoma , feeds externally and makes a protective , portable “purse” case . perhaps the original colonist species was a case maker or case making evolved as an enabling adaptation after its arrival on hawaii . most species of hyposmocoma , feed on plants , but some are carnivorous , feeding on snails .
this adult moth from the genus hyposmocoma was found in disturbed habitats in hawaii previously believed to be overrun by non - native and invasive species . © florida museum photo by akito kawahara
hyposmocoma is also unique because many species within the genus are aquatic or carnivorous , which is uncommon in lepidoptera . aquatic species may be used as a means for assessing environmental habitat quality , such as the amount of pollution in streams .
scientists believe hyposmocoma reached the pacific islands millions of years ago , long before the colonization of humans . on an island chain where diverse songbirds , flightless rails and rare endemic plants once thrived , it is increasingly valuable for researchers to protect any remaining native biodiversity .
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florida museum assistant curator of lepidoptera akito kawahara recently described three moth species in a zookeys study published in february 2012 . © florida museum photo by kristen grace
on the hawaiian islands , where isolated , vulnerable pieces of land are surrounded by thousands of miles of ocean , habitat destruction is something of a catchphrase .
it is well known how the arrival of humans about 1 , 000 years ago drastically changed the ecosystem with the introduction of invasive plants and animals . it has led to stricter policies for releasing non - native pets , increased regulations at trade ports and the emergence of restoration ecology , in which scientists strive to re - create a more native environment .
but within areas seemingly overcome by invasive plants and animals , one florida museum of natural history lepidopterist discovered three new native moth species .
similar to how snails carry a shell , this newly described species of fancy case caterpillar endemic to hawaii wears an ornate “case” throughout the larval stage of development . © florida museum photo by akito kawahara
“they move around carrying their home , ” kawahara said . “they are called fancy case caterpillars because they make very extravagant , beautiful cases that are ornamented with sand , branches , lichen or colorful insect parts . sometimes these cases resemble cigars , burritos , candy wrappers or purses . others simply look like the tree bark that they rest on . ”
“there’s an extraordinary diversity of these moths in hawaii and the total number may be well over 1 , 000 species , ” kawahara said . “they’re only found in hawaii and they’re very threatened . we initially thought purse cases may only include 10 species or so , but there are clearly a lot more . some species are dual entry , so the larva can peek out of one end of their case and then peek out of the other . ”
“it’s really important to focus conservation efforts in areas that are pristine and also to restore habitats that are disturbed , ” kawahara said .
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the hawaiian islands are remote from other terrestrial habitats . in evolutionary time , they are recent additions to the earth , with the oldest islands a little more than 1 million years old . the number of species that colonized the islands ( until recent times ) was low . these species landed in an area with diverse habitats that were largely uninhabited by other species . due to low competition for resources , species that found the island formed many new species as populations adapted independently to geographic locations with widely different conditions .
as in many tropical areas , invasive species and habitat destruction have led to a loss of many hawaiian species . scientists are studying and cataloging the unique species as part of plans to protect endangered species and unique habitats . as part of a comprehensive study , kawahara and rubinoff * have identified 3 new species of “fancy case”
jonathan neal is an associate professor of entomology at purdue university and author of the textbook , living with insects ( 2010 ) . this blog is a forum to communicate about the intersection of insects with people and policy . this is a personal blog . the opinions and materials posted here are those of the author and are in no way connected with those of my employer .
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ruckh , timothy ; porter , joshua r . ; allam , nageh k . ; feng , xinjian ; grimes , craig a . ; popat , ketul c .
the goal of current dental and orthopedic biomaterials research is to design implants that induce controlled and guided tissue growth , and rapid healing . in addition to acceleration of normal wound healing phenomena , these implants should result in the formation of a characteristic interfacial layer with adequate biomechanical properties . to achieve these goals , however , a better understanding of events at the bone - material interface is needed , as well as the development of new materials and approaches that promote osseointegration . here we present novel nanostructured nanoarrays from
nanotube arrays enhance osteoblast cell adhesion , proliferation and differentiation . the routes of fabrication of
nanotube arrays are flexible and cost - effective , enabling realization of desired platform topologies on existing non - planar orthopedic implants .
the structure factors of molten t a2o5 and n b2o5 have been measured by high - energy x - ray and pulsed neutron diffraction . these are compared to transmission - mode x - ray diffraction through a self - supported 15 - î¼m ion - beam sputtered amorphous
and niobia liquids are very close to isomorphous , as confirmed by measurement of a molten mixture , t a0 . 8n b1 . 2o5 . nonetheless , peak nb - o bond lengths are about 1 % shorter than those for ta - o , at temperatures , t * = t / tmelt , scaled to the melting points . mean coordination numbers are nm oâ5 . 6 ( 1 ) , no mâ2 . 23 ( 4 ) in the liquid state , and ntaoâ6 . 6 ( 2 ) , notaâ2 . 63 ( 8 ) in the solid . the liquids are built from five - and six - fold m - o polyhedra which connect principally by corner sharing , with a minority of edge sharing ; a - t a2o5 on the other hand has a local structure more akin to the crystalline polymorphs , built primarily from six - and seven - fold polyhedra , with a larger degree of edge sharing . the structural differences between liquid and amorphous t a2o5 , coupled with observations of increasing peak bond lengths upon cooling , are consistent with the interpretation that the amorphous film reaches a supercooled liquidlike metastable equilibrium during deposition . in other words , the amorphous film shares a common progenitor state with a hypothetical glass quenched from a fragile melt . in addition , we show that recent classical interatomic potentials do not fully reproduce the diffraction data , and infer that inclusion of attractive ( non - coulombic ) ta - ta interactions is important , particularly for obtaining the correct degree of edge sharing , coordination numbers , and densities . nanoscale inhomogeneity of the amorphous film is confirmed by the observation of small - angle x - ray scattering .
alderman , oliver l . g . ; benmore , c . j . ; neuefeind , joerg c .
the structure factors of molten ta 2o 5 and nb 2o 5 have been measured by high - energy x - ray and pulsed neutron diffraction . these are compared to transmission - mode x - ray diffraction through a self - supported 15 - î¼m ion - beam sputtered amorphous
alderman , oliver l . g . ; benmore , c . j . ; neuefeind , joerg c . ; . . .
brownian thermal noise in dielectric multilayer coatings limits the sensitivity of current and future interferometric gravitational wave detectors . in this work we explore the possibility of improving the mechanical losses of
, often used as the high refractive index material , by depositing it on a substrate held at elevated temperature . promising results have been previously obtained with this technique when applied to amorphous silicon . we show that depositing
on a hot substrate reduced the mechanical losses of the as - deposited coating , but subsequent thermal treatments had a larger impact , as they reduced the losses to levels previously reported in the literature . we also show that the reduction in mechanical loss correlates with increased medium range order in the atomic structure of the coatings using x - ray diffraction and raman spectroscopy . finally , a discussion is included on our results , which shows that the elevated temperature deposition of pure
coatings does not appear to reduce mechanical loss in a similar way to that reported in the literature for amorphous silicon ; and we suggest possible future research directions .
valve metals such as titanium ( ti ) , zirconium ( zr ) , niobium ( nb ) and tantalum ( ta ) that confer a stable oxide layer on their surfaces are commonly used as implant materials or alloying elements for titanium - based implants , due to their exceptional high corrosion resistance and excellent biocompatibility . the aim of this study was to investigate the bioactivity of the nanostructures of
( ta2o5 ) , niobia ( nb2o5 ) , zirconia ( zro2 ) and titania ( tio2 ) in accordance to their roughness and wettability . therefore , four kinds of metal oxide nanoporous and nanotubular ta2o5 , nb2o5 , zro2 and tio2 were fabricated via anodization . the nanosize distribution , morphology and the physical and chemical properties of the nanolayers and their surface energies and bioactivities were investigated using sem - eds , x - ray diffraction ( xrd ) analysis and 3d profilometer . it was found that the nanoporous ta2o5 exhibited an irregular porous structure , high roughness and high surface energy as compared to bare tantalum metal ; and exhibited the most superior bioactivity after annealing among the four kinds of nanoporous structures . the nanoporous nb2o5 showed a uniform porous structure and low roughness , but no bioactivity before annealing . overall , the nanoporous and nanotubular layers of ta2o5 , nb2o5 , zro2 and tio2 demonstrated promising potential for enhanced bioactivity to improve their biomedical application alone or to improve the usage in other biocompatible metal implants . pmid : 25837724
- based sol - gel coating for capillary microextraction on - line coupled to high - performance liquid chromatography .
a sol - gel organic - inorganic hybrid sorbent , consisting of chemically integrated tantalum ( v ) ethoxide ( taeo ) and polypropylene glycol methacrylate ( ppgm ) , was developed for capillary microextraction ( cme ) . the sol - gel sorbent was synthesized within a fused silica capillary through hydrolytic polycondensation of taeo and chemical incorporation of ppgm into the evolving sol - gel
network . a part of the organic - inorganic hybrid sol - gel network evolving in the vicinity of the capillary walls had favorable conditions to get chemically bonded to the silanol groups on the capillary surface forming a surface - bonded coating . the newly developed sol - gel sorbent was employed to isolate and enrich a variety of analytes from aqueous samples for on - line analysis by high - performance liquid chromatography ( hplc ) equipped with a uv detector . cme was performed on aqueous samples containing trace concentrations of analytes representing polycyclic aromatic hydrocarbons , ketones , alcohols , amines , nucleosides , and nucleotides . this sol - gel hybrid coating provided efficient extraction with cme - hplc detection limits ranging from 4 . 41pm to 28 . 19 pm . due to direct chemical bonding between the sol - gel sorbent coating and the fused silica capillary inner surface , this sol - gel sorbent exhibited enhanced solvent stability . the sol - gel
- based sorbent also exhibited excellent ph stability over a wide ph range ( ph 0 - ph 14 ) . furthermore , it displayed great performance reproducibility in cme - hplc providing run - to - run hplc peak area relative standard deviation ( rsd ) values between 0 . 23 % and 3 . 83 % . the capillary - to - capillary rsd ( n = 3 ) , characterizing capillary preparation method reproducibility , ranged from 0 . 24 % to 4 . 11 % . the results show great performance consistency and application potential for the sol - gel
- ppgm sorbent in various fields including biomedical , pharmaceutical , and environmental areas . copyright â© 2017 elsevier b . v . all rights reserved .
bassiri , riccardo ; liou , franklin ; abernathy , matthew r . ; . . .
( a - taâoâ ) is a technologically important material often used in high - performance coatings . understanding this material at the atomic level provides a way to further improve performance . this work details extended x - ray absorption fine structure measurements of a - taâoâ coatings , where high - quality experimental data and theoretical fits have allowed a detailed interpretation of the nearest - neighbor distributions . it was found that the tantalum atom is surrounded by four shells of atoms in sequence ; oxygen , tantalum , oxygen , and tantalum . a discussion is also included on how these models can be interpreted within the context of published crystalline taâoâ and other a - tâoâ studies .
cryogenic measurements of mechanical loss of high - reflectivity coating and estimation of thermal noise .
we report on low - frequency measurements of the mechanical loss of a high - quality ( transmissivity t < 5 ppm at î» ( 0 ) = 1064 nm , absorption loss < 0 . 5 ppm ) multilayer dielectric coating of ion - beam - sputtered fused silica and titanium - doped
in the 10 - 300 k temperature range . a useful parameter for the computation of coating thermal noise on different substrates is derived as a function of temperature and frequency .
, titania , and hafnia are important oxides for biomedical implants , optics , and gate insulators . understanding the effects of oxide doping is crucial to optimize performance in these applications . however , no molecular dynamics potentials have been created to date that combine these and other oxides that would allow computational analyses of doping - dependent structural and mechanical properties . we report a novel set of computationally efficient , two - body potentials modeling van der waals and covalent interactions that reproduce the structural and elastic properties of both pure and doped amorphous oxides . in addition , we demonstrate that the potential accurately produces energy barrier distributions for pure and doped samples . the distributions can be directly compared to experiment and used to calculate physical quantities such as internal friction to understand how doping affects material properties . future analyses using these potentials will be of great value to determine optimal doping concentrations and material combinations for myriad material science applications .
ttedesign philosophy of mc - ar - coatings can be divided into two categories : a ) restriction to two film materials , namely one high - index and one low - index material and b ) use of medium - index layers in addition to high - and low - index layers . both philosophies have advan - tages and drawbacks . in case a ) the total number of layers necessary to obtain a required reflectance curve has to be higher . thus in case of production errors it can be a problem to find out which layer was responsible for a deviation of the measured reflectance from the nominal one . in case b ) using more than two materials reduces the total number of layers and consequently , pinpointing the cause of even small production errors is made simpler . unfortunately there are not many materials commercially available which can be used to make hard , durable and robust films in the medium - index range namely between n = 1 . 65 and n = 2 . 00 . in this paper the results of homogeneous mixtures of alumina ( al203 ) and
( ta205 ) used for eb - gun evaporated medium - index films in ar - coatings is presented . it is shown that by proper adjustment of the weight percentages of the oxide mixture one can get homogeneous films in this index range . a number of design examples show the favourable application of such layers in ar - coatings . among the most important ones is the well known qhq - design for bbar - coatings as well as ar - designs of the multiple half wave type with extended bandwidth . further applications of the mixed - oxide layers are ar - coatings for cemented optical elements and beam splitters .
the case of fused silica as a substrate material for the next line of future detectors , such as advanced ligo . the low levels of internal loss in bulk silicon samples is also of interest due to the silicon ' s high thermal conductivity . this is relevant when considering third generation detectors , that is , beyond the advanced ligo design , where significant thermal loading is anticipated due to the increased levels of laser power required for improved shot noise performance . another significant source of thermal noise in the optics of current interferometers arises from the mechanical loss associated with the applied optical coatings required for high reflectivity . results presented in chapter 4 show that the mechanical loss is predominantly associated with the
with titania can reduce the mechanical loss by a factor of approximately two . silicon may also be a useful material for the construction of low mechanical loss suspension elements . chapter 6 details measurements of 92mum thick silicon flexures for use as suspension elements which show the mechanical loss to reach ï ( w ) = 4 . 4 x 10 - 7 at 85 k . the various sources of loss are considered , both internal and external to the samples , and presented . the level of internal loss is consistent at higher temperatures with thermoelastic effects and at lower temperatures to be dominated by surface loss in addition to perhaps some other loss mechanism . the measurements in chapters 5 and 6 suggest that silicon may be a suitable material for both mirrors and suspension elements .
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yielded very corrosion resistant , orthorhombic zirconia ceramics . the powders for those novel ceramics were made via the sol - gel technique by hydrolysis of the respective metal propoxides ; a method which required dry - box techniques during the preparation of the alkoxides . in these studies the authors investigated the fabrication of precursor material from aqueous solutions . the preparation of aqueous solutions of salts of zirconium , niobium and tantalum is hampered by rapid hydrolysis . premature hydrolysis of the chlorides and oxichlorides of niobium , tantalum and zirconium can be , however , prevented in aqueous solutions of oxalic acid . thus the authors investigated the coprecipitation of hydroxides as precursors by reacting oxalic acid solutions of the respective cations with aqueous ammonia . in addition they studied the effects of calcination and of hydrothermal conversion of the hydroxides to oxides on the powder characteristics and on the mechanical properties of the niobia and
mechanical losses in dielectric mirror coatings of interferometric gravitational wave detectors are a main issue for the proposed advanced generation of gravitational wave detectors . recent investigations have shown that the mechanical loss of the dielectric mirror coatings (
/ silica stacks ) is probably the main contribution to the detector noise . there are indications that among both coating materials
gives the major contribute to mechanical loss . experimental details of a measuring setup and investigations of the temperature dependency of the mechanical dissipation in thin
) . however , mechanical loss in the ta 2 o 5 / sio 2 coatings may limit the design sensitivity for advanced detectors . we have investigated sources of mechanical loss in the ta 2 o 5 / sio 2 coatings , including loss associated with the coating - substrate interface , with the coating - layer interfaces and with the coating materials . our results indicate that the loss is associated with the coating materials and that the loss of ta 2 o 5 is substantially larger than that of sio 2
konstantinov , a . a . ; sazonova , t . e . [ vsesojuznyj nauchno - isledovatel ' skij institut im . d . i . mendeleeva , leningrad , sssr ( russian federation )
abernathy , matthew r . ; harry , gregory m . ; travasso , flavio ; martin , iain ; reid , stuart ; rowan , sheila ; hough , jim ; fejer , martin m . ; route , roger ; penn , steve ; armandula , helena ; gretarsson , andri
second - generation interferometric gravitational - wave detectors will operate at temperatures noticeably above room temperature . study was done to determine what effect elevated temperatures would have on the q and coating thermal noise of the detector mirrors . results show that increased temperature increases loss angle in a manner that is more significant at higher frequencies . trends show that the increased temperature will have a negligible effect at the low ( 100 hz ) frequencies important to second - generation detectors
hacker , e ; lauth , h ; meyer , j ; weissbrodt , p [ zeiss jena gmbh , jena ( germany , f . r . ) ; wolf , r ; zscherpe , g [ ingenieurhochschule mittweida ( germany , f . r . ) ; heyer , h [ sektion physik , friedrich - schiller - univ . jena ( germany , f . r . )
( ta { sub 2 } o { sub 5 } ) prepared by reactive r . f . diode and d . c . plasmatron sputtering were investigated for the influence of structural properties on the 1064 nm laser damage resistance . using various methods of characterizing the compositional , crystallographic , microstructural and optical properties , it was found that the damage thresholds are directly related to the content of oxygen in the films in excess of the stoichiometric values , whereas grain sizes and refractive indices show no systematic influences valid for both oxide materials . the highest oxygen - to - metal atomic ratios and thus the highest damage threshold were achieved by the use of r . f diode sputtering . x - ray photospectroscopy investigations of
coatings with different oxygen - to - tantalum atomic ratios up to 2 . 75 revealed for both constituents of the oxide only binding energies representative for tantalum pentoxide . ( orig . ) .
a new method is presented for elemental and molecular analysis of halogen - containing samples by glow discharge time - of - flight mass spectrometry , consisting of detection of negative ions from a pulsed rf glow discharge in argon . analyte signals are mainly extracted from the afterglow regime . . . . . . be used to study the distribution of a tantalum fluoride layer within the anodized
layer . further , comparison is made with data obtained using glow - discharge optical emission spectroscopy , where elemental fluorine can only be detected using a neon plasma . the ionization mechanisms responsible . . . . . . for the formation of negative ions in glow discharge time - of - flight mass spectrometry are briefly discussed . . . .
- doped monoclinic europia were studied at temperatures up to 1500 0 c using the sonic resonance technique . unit cell parameters between 25c and 1000 0 c for monoclinic eu 2 o 3 were calculated from high temperature x - ray diffractometer data . large - grained monoclinic specimens having less than 6 . 0 ta cation percent substitution exhibited anomalous elastic behavior when thermally cycled . compositions above this addition level exhibited linear elastic behavior . internal friction values also varied abnormally with grain size , composition , and temperature . the anomalous behavior was attributed to microcracking caused by thermal expansion anisotropies . the critical grain size was found to be approximately 14 î¼m . the high temperature diffractometry measurements supported the postulate that the grain coarsening effect associated with sintered monoclinic eu 2 o 3 is the controlling factor for microcracking
proton conducting tantalum oxide films were deposited by spin coating using a sol - gel process . the coating solutions were prepared using ta ( oc { sub 2 } h { sub 5 } ) { sub 5 } as a precursor . x - ray diffraction studies determined that the sol - gel films , heat treated at temperatures below 400 c , were amorphous . films heat treated at higher temperatures were crystalline ta { sub 2 } o { sub 5 } . the solar transmission values ( t { sub s } ) of
films on glass generally range from 0 . 8 - - 0 . 9 depending on thickness . the refractive index and the extinction coefficient were evaluated from transmittance characteristics in the uv - vis - nir regions . the refractive index values calculated at 550 nm increased from 1 . 78 to 1 . 97 with increasing heat treatment from 150 to 450 c . the films heat treated at different temperatures showed low absorption with extinction coefficients of less than k = 1x10 { sup - 3 } in the visible range . spectrophotometric and impedance spectroscopic investigations performed on ta { sub 2 } o { sub 5 } films revealed that these films have protonic conductivity of 3 . 2x10 { sup - 6 } s / cm . the films are suitable for proton conducting layers in electrochromic ( ec ) devices .
zarodyshevyh jaic nabljudalos ' posle in { sup e } kcii okisi tritija do zarazhenija virusom . cherez dva chasa posle ino - kuljacii agenta infekcii bylo obnaruzheno tysjachekratnoe , uvelichenie virusa v otnosjashhihsja k horionu allantoidnyh zhidkostjah obrabotannyh jaic . kogda , cherez vosem ' chasov posle infekcii v otnosjashhihsja k horionu allantoidnyh zhidkostjah kontrol ' nyh jaic okazalos ' znachitel ' noe kolichestvo virusa , id { sub 50 } obrabotannyh tritiem jaic sostavljal 10 { sup - 5 , 6 } ; obe serii imeli id { sub 50 } v razmere 10 { sup - 7 . 5 } cherez 24 chasa posle infekcii . kolichestvo virusa v plenkah , obrabotannyh tritiem jaic takzhe vozroslo . jetot virus byl osvobozhden pri pomoshhi udalenija i promyvanija
. en la memoria se facilitan detalles relativos a su construccion y a las normas de seguridad que se han observado en el proyecto . las determinaciones dosimetricas se han efectuado con ayuda de cuatro tipos de aparatos diferentes : 1 . camaras de ionizacion 2 . calorimetros 3 . dosimetros de fricke 4 . peliculas fotograficas . en la memoria se hace asimismo una descripcion general del campo de irradiacion gamma y se dan detalles referentes a la posicion de la fuente . la intensidad de irradiacion es de unos 100 roentgens / hora a una distancia de 1 m . las plantas sometidas a la irradiacion se cultivan en un campo de 15 m de radio . se indican brevemente los diferentes productos que se han sometido a irradiacion en las dos instalaciones . ( author ) [ russian ] v doklade opisyvayutsya ustanovka dlya obluchenij na co { sup 60 } i pole gammaluchej v otdelenii sel ' skogo khozyajstva nauchno - issledovatel ' skogo tsentra v rizo . ustanovka dlya obluchenij na co { sup 60 } soderzhit 1800 kyuri co { sup 60 } . dayutsya detali konstruktsii , a takzhe ukazyvayutsya mery bezopasnosti , kotorye uchteny v konstruktsii ustanovki . dozimetriya proizvoditsya pri pomoshchi chetyrekh razlichnykh metodov : 1 . ionizatsionnykh kamer ; 2 . kalorimetrii 3 . dozimetra frikke 4 . fotograficheskikh
daetsya obshchee opisanie polya gamma - izluchenij , vklyuchaya detali raspolozheniya istochnikov . norma dozirovaniya - priblizitel ' no 100r / ch na rasstoyanii v odin metr . dlya vyrashchivaniya obluchaemykh rastenij beretsya pole s radiusom v 15 metrov . daetsya kratkoe ukazanie kategorii produktov , podvergaemykh oblucheniyu v dvukh ustanovkakh . ( author )
campbell , r b ; grunberg , l ; milne , a a ; wright , k h . r . [ lubrication , wear and mechanical engineering aspects of corrosion division , national engineering laboratory , thorntonhall , glasgow ( united kingdom )
chastitsy okisi zheleza ispol ' zuyutsya dlya izucheniya ikh roli v protsesse iznosa . reaktivnost ' poverkh - nosti zakalennykh metallov izuchalas ' s pomoshch ' yu mechennoj uglerodom - 14 stearinovoj kisloty i rastvora sery - 35 . skorost ' reaktsii v primesi masla dlya shesteren analizirovalas ' putem propuskaniya korotkikh impul ' sov ehlektrotoka po metallicheskim provodam , opushchennym v rastvory soedinenij , mechennykh seroj - 35 i fosforom - 32 . sozdanie stojkikh k istiraniyu
na poverkhnosti zub ' ev shesterenok izuchalos ' kak funktsiya nagruzki , skorosti i vremeni raboty . vopros , vstrechayushchijsya vo mnogikh iz vidov ehtogo primeneniya , sostoit v prevrashchenii izmeryaemoj aktivnosti v absolyutnye kolichestva materialov , prisutstvuyushchikh na poverkhnosti
ili v produktakh iznosa . dlya ehtoj zhe tseli ispol ' zovalis ' metody kalibrovaniya . ( author )
v kachestve radiatora protonov . polimery n21 i n9 2 primenjalis ' predvaritel ' no v ispytatel ' noj ammiachnoj jemul ' sii . bylo ustanovleno , chto polimer no 1 ne okazyvaet zametnogo vlijanija na fotohimicheskie svojstva
{ sup 12 } c / s para { zeta } = 1 . 0 . si estas y otras particularidades observadas son anomalias de kohn , sus posiciones son compatibles con las dimensiones de la superficie de fermi propuesta por lomer para los metales de la columna v . se formula la hipotesis de que las sorprendentes diferencias existentes entre la relacion de dispersion del niobio y la del molibdeno ( metales que , segun se cree , poseen estructuras de banda muy semejantes ) reflejan diferencias en las energias de fermi y , por tanto , en las superficies de fermi de estos materiales . ( author ) [ russian ] dispersionnoe sootnoshenie chastota / volnovoj vektor v ( q ) dlja obychnyh vidov kolebanij nekotoryh ob { sup e } mno - centrirovannyh kubicheskih kristallov perehodnyh metallov bylo nedavno izmereno pri komnatnoj temperature . krivye dispersii dlja niobija , izmerennye nakagovoj i vudsom , projavili nekotorye ochen ' neobychnye cherty , i rezul ' taty mozhno bylo privesti v sootvetstvie tol ' ko s pomoshh ' ju modeli born fon karmana , esli vkljuchit ' vzaimodejstvija s ochen ' otdalennymi chlenami rjada dal ' she vos ' mogo . posledujushhie izmerenija vudsom
dali ochen ' pohozhie rezul ' taty . jeto ne udivitel ' no , poskol ' ku niobij i tantal nahodjatsja v v gruppe periodicheskoj tablicy i mnogie iz ih jelektronnyh svojstv odinakovy . izmerenija krivyh dispersij molibdena vudsom i chenom i vol ' frama chenom i brok - hauzom pokazali , chto , hotja u jetih metallov , kotorye nahodjatsja v gruppe vi periodicheskoj tablicy , dispersionnye sootnoshenija javljajutsja analogichnymi , jeti dispersionnye sootnoshenija sil ' no otlichajutsja ot dispersionnyh sootnoshenij dlja niobija i
, nahodjashhihsja v gruppe v . osnovnye cherty u ( q ) dlja molibdena i vol ' frama ochen ' blizko opisyvajutsja tret ' im chlenom rjada simmetrichnoj po osjam silovoj modeli born - fon karmana , hotja nekotorye vazhnye cherty ne vosproizvodjatsja jetoj model ' ju . odnoj iz takih chert javljaetsja razitel ' naja anomalija v prodol ' noj [ { zeta } { zeta } { zeta } ] vetvi ( l ) dlja molibdena , gde
sobre las emulsiones rapidas y lentas con elevada concentracion de plata . en las emulsiones que se usan para la medicion de dosis elevadas y que se revelan en presencia de retardadores , se ha determinado la influencia ejercida por la energia y la atenuacion de la imagen latente sobre la precision de las determinaciones . por ultimo , se describen los errores de la evaluacion fotografica de dosis elevadas hallados aplicando metodos estadisticos al analisis de los resultados experimentales . se examina tambien el incremento del error en las regiones de debil y fuerte ennegrecimiento . tambien se consideran los errores debidos a la calibracion de los aparatos , la influencia de la energia , la atenuacion de la imagen latente , el tratamiento quimico y la medicion del ennegrecimiento . la hipotesis de que la dosis medida con dosimetros de pelicula corresponde a la dosis recibida por el organismo entero , constituye un error que no se toma en consideracion . ( author ) [ russian ] v jetoj rabote opisyvaetsja fotograficheskaja dozimetrija ionizirujushhej radiacii v diapazone ot 10 millirad do 1000 rad ( dlja gamma - izluchenija bolee vysokoj intensivnosti ) . pri jetom metode ispol ' zujutsja dve fotoplenki s razlichnoj jemul ' siej , kotorye odnovremenno pomeshhajut v odin i tot zhe plenochnyj dozimetr . sushhestvennoj chertoj jetogo metoda javljaetsja to , chto dozy v vysheprivedennom diapazone mogut byt ' opredeleny bez znanija o tom , chto imelo mesto obluchenie bol ' shimi dozami , s tochnost ' ju luchshej chem { + - } 25 % v predelah vsego diapazona doz ( doveritel ' nyj interval 95 % ) , a takzhe to , chto jenergiju obluchenija v plenke mozhno opredelit ' s horoshej approksimaciej . rassmatrivajutsja pribory , vidy
i himicheskaja obrabotka , kotorye pozvoljajut proizvodit ' jeti izmerenija . opisyvaetsja princip izgotovlenija densitometra , s pomoshh ' ju kotorogo mozhno izmerit ' potemnenie fotoplenki s odinakovoj tochnost ' ju v diapazone ot d = 0 do d = 6 . takim putem mozhno ispol ' zovat ' vsju oblast ' imejushhegosja
tecnicas confirman la opinion de que los radioisotopos encierran enormes promesas en el terreno cientifico y tecnico . por lo que se refiere a las fuentes de rayos x , puede decirse que todo cuanto se realiza en el terreno de la tecnologia de los rayos x , salvo la determinacion de la estructura de los cristales , puede hacerse con mayor sencillez recurriendo a los medios citados . es mas , si se emplearan fuentes de muchos curies , puede que incluso llegue a ser posible efectuar esas determinaciones . ( author ) [ russian ] prozvedennye v ehtoj laboratorii za poslednie sem ' , let issledovaniya ustanovili tochnye usloviya obratnogo rasseyaniya beta - chastits , i ehti metody byli dopolneny metodami ispol ' zovaniya vozbuzhdennykh izotopami rentgenovskikh luchej . vozbuzhdennye takim sposobom rentgenovskie luchi privlekli . shirokoe vnimanie vo vsem svete i vo mnogikh sluchayakh oni revolyutsionizirovali metody promyshlennoj kalibrovki . v nastoyashchem doklade razbirayutsya primeneniya k tochnoj abzorbtsiometrii , izmereniyu tolshchiny
, opoznovaniyu i kolichestvennomu opredeleniyu veshchestv putem izmereniya absorbtsii po krayam , a takzhe k bumazhnoj khromatografii . v poslednem sluchae , khromato grammy mogut izuchat ' sya posredstvom beta - absorbtsii , absorbtsii rentgenovskimi luchami ili vozbuzhdeniem rentgenovskikh luchej v razlichnykh zonakh bombardirovkoj beta - luchami . sravnivayutsya i otsenivayutsya ehti razlichnye podkhody . byl izuchen tselyj ryad mikrokhimicheskikh metodov i libo posredstvom beta - absorbtsii , libo posredstvom vozbuzhdeniya rentgenovskikh luchej beta - chastitsami mogut byt ' opoznany i opredeleny nebol ' shie kolichestva veshchestv . nizshie predely detektsii ne tak : maly , kak ehto dostizhimo metodom radioaktivnykh indikatorov , no imeetsya ryad drugikh preimushchestv , glavnoe iz kotorykh zaklyuchaetsya v tom , chto operatsii proizvodyatsya s zadelannymi istochnikami , chto pochti sovershenno isklyuchaet vozmozhnost ' radioaktivnogo zarazheniya . na osnovanii ehtikh dannykh byli
peliculas y borra d e polietileno para dosis de exposicion a rayos gamma de { sup 60 } co hasta 8 , 0 x 10 { sup 5 } r / h . determinaron tambien la velocidad de transformacion del estireno en su homopoirmero , en las suspensiones de borra . examinaron al microscopio las peliculas injertadas a fin de evaluar la proporcion de homopolfmero ocluido . los resultados obtenidos indican que la mayor parte del incremento de peso en las muestras de pelicula corresponde al homopolfmero ocluido . en las pruebas con borra , en las cuales el incremento de peso se debe principalmente al copolimero injertado , dicho incremento es aproximadamente proporcional a la dosis y la velocidad de reaccion es casi proporcional a la rafe cuadrada de la intensidad de la dosis gamma . la reducida energia de activacion correspondiente a la velocidad de reaccion excluye la posibilidad de controlar la difusion en la borra y en las peliculas delgadas para intensidades de exposicion inferiores a 10 { sup 5 } r / h . en los experimentos con borra a 18 { sup o } c e intensidades de 7 , 2 x 10 { sup 4 } r / h , la velocidad de formacion del homopolfmero coincide con el valor ya conocido para la polimerizacion del estireno puro . la energia de activacion , a saber , 3 , 5 kcal / mol , representa practicamente la mitad de la indicada para el monomero puro . ( author ) [ russian ] izuchenie opublikovannykh dannykh ob initsiirovannoj oblucheniem privitoj polimerizatsii stirola k plenkam poliehtilena nizkoj plotnosti pokazyvaet , tfgo skorost ' prirosta vesa lish ' neznachitel ' no zavisit ot moshchnosti gamma - oblucheniya i tolshchiny plenki . pokazano , chto modeli , primenyavshiesya ranee issledovatelyami dlya ob { sup y } asneniya dannykh prirosta vesa dlya otsenki konstant skorosti , ne godyatsya . privedeny ehksperimental ' nye dannye po privivaniyu pri temperaturakh 18 { sup o } c i 40 { sup o } c s ispol ' zovaniem poliehtilenovykh
, legkoj melkokristallicheskoj kal ' tsinirovannoj sody i istochnika co { sup 60 } s gamma - izlucheniem moshchnost ' yu do 8 , 0 x 10 { sup 5 } r / ch . izmerena
periodico , es particularmente adecuado para algunos de estos estudios . las ventajas do este elemento estriban , en sus propiedades nucleares . la memoria resume las propiedades quimicas de los compuestos de tecnecio y las compara con las de los compuestos correspondientes de { sup 51 } cr , de molibdeno y de wolframio , que con tanta frecuencia se emplean en el estudio de la inhibicion . la memoria describe seguidamente ciertos estudios experimentales como ejemplo de los usos a que se ha destinado el tecnecio en los trabajos de este tipo . entre ellos menciona estudios empiricos de su accion como eficaz inhibidor de la corrosion del hierro , y observaciones de la actividad de superficie realizadas durante periodos largos de tiempo . otros estudios efectuados con { sup 99 } tc y con { sup 131 } i han demostrado la importancia de la adsorcion competitiva de iones en la determinacion de la cinetica de los procesos de corrosion y de inhibicion . como tercer ejemplo , describe como las propiedades excepcionales del tecnecio han permitido distinguir claramente las contribuciones relativas del oxigeno de las del inhibidor oxidante en el mantenimiento de la pasividad . ( author ) [ russian ] sredi faktorov , vkhodyashchikh v fundamental ' noe izuchenie ehlektrokhimicheskikh protsessov korrozii i tormozheniya , vydelyayutsya v chastnosti sleduyushchie : a ) razlichnye vidy adsorbtsionnykh yavlenij ; b ) ionoobmennye svojstva passivnykh
; c ) ehlektrokhimicheskaya kinetika kak anodnykh , tak i katodnykh protsessov , proiskhodyashchikh mezhdu metallom i korrozijnoj sredoj . teper ' pri pomoshchi radioizotopov mozhno provesti nekotorye issledovaniya ehtikh yavlyaenij , kotorye nevozmozhno osushchestvit ' obychnymi sredstvami . tekhnetsij , gomolog margantsa v periodicheskoj sisteme , okazalsya ves ' ma podkhodyashchim dlya nekotorykh ehtikh issledovanij . ego yadernye svojstva krajne interesny u ehtom otnoshenii . v doklade kratko izlagayutsya khimicheskie svojstva soedinenij tekhnetsiya , protivopostavlennye svojstvam
moleculas blanco en distintas condiciones de dosificacion . los experimentos en curso sobre moleculas analogas en tamano a las del blanco han contribuido a la aclaracion de los mecanismos de recombinacion de los atomos de retroceso . particular interes reviste el rendimiento de productos con un atomo de carbono mas que el blanco , que resultan de una reaccion de adicion . la localizacion del atomo adicional en una molecula blanco que tenga varios lugares de adicion proporciona informacion sobre la naturaleza del proceso . cuando el atomo de retroceso es moderado y su energia disminuye hasta el punto en que es posible la formacion de un enlace , al menos temporal , el exceso de energia que el atomo llc cede al sistema puede originar la ruptura de otros enlaces del complejo activado , lo que suele dar origen a un producto de dos atomos de carbono . si el complejo es capaz de conservar su integridad , suele resultar un producto de adicion . por tanto , la comparacion del rendimiento de compuestos de dos atomos de carbono ( acetileno , etileno y etano ) y de productos de adicion proporciona una informacion valiosa sobre la energia a la que pueden formarse enlaces estables , y sobre la naturaleza del grupo que contiene el { sup 11 } c y que participa en la reaccion . ( author ) [ russian ] uglerod - 11 obrazuetsja v rezul ' tate reakcii c { sup 12 } ( { gamma } , n ) c { sup 11 } v puchke tormoznogo izluchenija v sinhrotrone s jenergiej jelektronov 70 mjev . v kachestve veshhestva misheni primenjalis ' zhidkie uglevodorody s pjat ' ju i shest ' ju atomami ugleroda , v tom chisle normal ' nye razvetvlennye i aliciklicheskie pentany i geksany , a takzhe benzol . povedenie c { sub 11 } izuchalos ' metodom gazohromatograficheskogo razdelenija produktov , scheta aktivnosti c { sub 11 } v gazovom potoke v kamere , pomeshhennoj v scintilljacionnyj schetchik kanal ' nogo tipa . v kazhdom jeksperimente vyhody razlichnyh produktov sravnivalis ' s vyhodom acetilena kak vnutrennego standarta , a takzhe libo s pokazanijami registratora
predstavljajutsja v vide asimetrogammagramm i razdel ' nyh levogo i pravogo fotograficheskih dvuhrazmernyh izobrazhenij . impul ' sy ot kazhdogo detektora podajutsja na kontur usilitel ' - diskriminator i zatem na differencial ' nyj kontur , kotoryj pechataet levuju ili pravuju otmetki s cel ' ju pokaza preobladanija koncentracii radioaktivnosti sleva ili sprava . impul ' sy ot kazhdogo kontura usiljtel ' - diskriminator podajutsja takzhe na pereschetnye ustrojstva , kotorye v svoju ochered ' vozbuzhdajut lampy , ustanovlennye v svetonepronicaemom pomeshhenii . dve lampy , intensivnost ' sveta kotooyh poedstavljaet soboj funkciju aktivnosti , izmerennoj sootvetstvujushhimi detektorami , montirujutsja na obshhej podstavke , peredvigaemoj s pomoshh ' ju dvigatelej sel ' sina v sisteme detektora sinhronno s generatorami sel ' sina , tem samym davaja vozmozhnost ' primenjat ' ustanovlennuju na rasstojanii registrirujushhuju ustanovku . cilindricheskie linzy fokusirujut lampovye istochniki na plenku , pri jetom registracija kak sprava , tak i sleva osushhestvljaetsja odnovremenno na rentgenovskoj plenke razmerom 28 ch 36 sm . hotja operator mozhet ustanovit ' sootvetstvujushhuju predvaritel ' no opredelennuju velichinu srednej sily toka lampy v shirokom diapazone skorosti scheta , operatoru predostavljaetsja bol ' shaja svoboda v svjazi s nalichiem v kassete treh
, kazhdaja iz kotoryh obespechivaet optimal ' nuju kontrastnost ' v razlichnom diapazone skorosti scheta . pacientam vvodilis ' 350 mkjuri joda - 131 s syvorotochnym al ' buminom cheloveka posle predvaritel ' noj obrabotki rastvorom ljugolja . skennirovanie osushhestvljalos ' cherez 24 - 72 chasa . obychno bylo dostatochno poluchenija odnoj skennogrammy . u nekotoryh pacientov skennogrammy snimalis ' povtorno v peredne - zadnem napravlenii . v period s sentjabrja 1961 goda po nojabr ' 1962 goda u 653 pacientov bylo snjato 789sken - nogramm . u 109 pacientov iz jetogo chisla diagnoz podtverdilsja , u 88 pacientov byli obnaruzheny opuholi . byla ustanovlena lokalizacija 23 iz 30 glioblastom i