former neglect of charity which brought you to your present state of destitution ; and now, again, you wish to rob others. i am afraid that in the coming ages you will have still greater poverty and distress ; — i am sorry for you beforehand. " with these words he followed his companions into the monastery, while the thieves left the grain and went away, all the monks, of whom there were several hundred, doing homage to his conduct and courage. - when he had finished his noviciate and taken on him the obligations of the full buddhist orders, his earnest courage, clear intelligence, and strict regulation of his demeanour were conspicuous ; and soon after, he undertook his journey to india in search of complete copies of the [ vinaya - pitaka ]. what follows this is merely an account of his travels in india and return to china by sea, condensed from his own narrative, with the addition of some marvelous incidents that happened to him, on his visit to the vulture peak near rajagriha. - it is said in the end that after his return to china, he went to the capital ( evidently nanking ), and there, along with the indian sramana buddha - bhadra, executed translations of some of the works which he had obtained in india ; and that before he had done all that he wished to do in this way, he removed to king - chow ( in the present hoo - pih ), and died in the monastery of sin, at the age of eighty - eight, to the great sorrow of all who knew him. it is added that there is another larger work giving an account of his travels in various countries. - such is all the information given about our author, beyond what he himself has told us. fa - hien was his clerical name, and means " illustrious in the law, " or " illustrious master of the law. " the shih which often precedes it is an abbreviation of the name of buddha as sakyamuni, " the sakya, mighty in love, dwelling in seclusion and silence, " and may be taken as equivalent to buddhist. it is sometimes said to have belonged to " the eastern tsin dynasty " ( a. d. 317 - 419 ), and sometimes to " the sung, " that is, the sung dynasty of the house of liu ( a. d. 420 - 478 ). if he became a full monk at the age.... of twenty, and went to


, and sometimes to " the sung, " that is, the sung dynasty of the house of liu ( a. d. 420 - 478 ). if he became a full monk at the age.... of twenty, and went to india when he was twenty - five, his long life may have been divided pretty equally between the two dynasties. - xian, fa ; tr. by james legge ( 1886 ). a record of buddhistic kingdoms ; being an account by the chinese monk fa - hien of his travels in india and ceylon, a. d. 399 - 414, in search of the buddhist books of discipline. the clarendon press, oxford. - hien, fa ; tr. from the chinese by herbert a giles ( 1877 ). record of the buddhistic kingdoms by fa hien ( 414 ad ). trubner & co., london. - online edition of the record of buddhistic kingdoms, university of adelaide library, australia. - buddhism in china - fa hien cave - silk road transmission of buddhism - song yun - zhang qian - zheng he - this article incorporates text from the medical times and gazette, volume 1, a publication from 1867 now in the public domain in the united states. - the medical times and gazette, volume 1. london : john churchill. 1867. p. 506. retrieved february 19, 2011. ( original from the university of michigan ) - legge, james 1886. a record of buddhistic kingdoms : being an account by the chinese monk fa - hien of his travels in india and ceylon ( a. d. 399 - 414 ) in search of the buddhist books of discipline. oxford, clarendon press. reprint : new york, paragon book reprint corp. 1965. isbn 0 - 486 - 21344 - 7 - beal, samuel. 1884. si - yu - ki : buddhist records of the western world, by hiuen tsiang. 2 vols. translated by samuel beal. london. 1884. reprint : delhi. oriental books reprint corporation. 1969. ( also contains a translation of faxian ' s book on pp. xxiii - lxxxiii ). - hodge, stephen " the textual transmission of the mahayana mahaparinirvana - sutra " ( 2009 & 2012 ), http : / / www. buddhismuskunde. uni - hamburg. de / fileadmin / pdf / publikationen / the _ textual _ transmisssion _


| | this article needs attention from an expert on the subject. ( december 2011 ) | a fail - safe or fail - secure device is one that, in the event of failure, responds in a way that will cause no harm, or at least a minimum of harm, to other devices or danger to personnel. " fail - safe [ ty ] " should not be confused with " fail - secur [ ity ]. " a fail - secure component of a system secures that system ( or at least the portion to which the component is dedicated ) in the event of a failure either of that component or elsewhere in the system. for example, during a failure of an ingress - egress control system, e. g., a user propping a door open somewhere in a building, a fail - secure lock will close, lock, and remain locked even when a user attempts to unlock it with the key that the user usually employs. in such a case, an independent release, such as a reboot or disarming of the securing mechanism, is required. in contrast, a component may be considered fail - safe even if its failure does not secure the system. for example, if a door locked from the inside is left unlocked or is unlocked at the wrong time, it has failed ( in some cases, along with the entire system ), the door may be ( but is not necessarily ) fail - safe if its being unlocked does not open it or attract additional attention to its unlocked state. significantly, despite popular belief to the contrary, a system ' s being " fail - safe " means not that failure is impossible / improbable, but rather that the system ' s design prevents or mitigates unsafe consequences of the system ' s failure ; that is, if and when a " fail - safe " system " fails ", it is " safe " or at least no less safe than when it is operating correctly. mechanical or physical - aircraft landing on an aircraft carrier increases the throttle to full power at touchdown. if the arresting wires fail to capture the plane, it is able to take off again. - coiling / rolling fire doors that are activated by building alarm systems or local smoke detectors must close automatically when signaled regardless of power. in case of power outage the coiling fire door does not need to close, but must be capable of automatic closing when given a signal from the building alarm systems or smoke detectors. a temperature sensitive fusible link may be employed to hold the fire doors open against gravity or


hoist cables were to fail. - various devices that operate with fluids use fuses or valves as a fail - safe mechanism. - a railway semaphore signal is designed so that should the cable controlling the signal break, the arm returns to the " danger " position, preventing any trains passing the inoperative signal. - on diving watches, the rotating bezel used to measure dive time contains a ratchet so it can only be turned counter - clockwise. if the bezel is inadvertently rotated during the dive, it will only rotate so as to give a false reading of increased time spent below, prompting the underwater diver to return to the surface earlier than intended, rather than later. this protects the diver from, for example, underestimating their decompression obligation, an error which could result in decompression sickness. electrical or electronic - many devices are protected from short circuit with fuses. the destruction of the fuse will prevent destruction of the device. - avionics using redundant systems to perform the same computation with voting logic to determine the " safe " result. - traffic light controllers use a conflict monitor unit to detect faults or conflicting signals and switch an intersection to all flashing red, rather than displaying potentially dangerous conflicting signals, e. g. showing green in all directions. - the automatic protection of programs and / or processing systems when a computer hardware or software failure is detected in a computer system. a classic example is a watchdog timer. see fail - safe ( computer ). - a control operation or function that prevents improper system functioning or catastrophic degradation in the event of circuit malfunction or operator error ; for example, the failsafe track circuit used to control railway block signals. - the iron pellet ballast on the bathyscaphe is dropped to allow the submarine to ascend. the ballast is held in place by electromagnets. if electrical power fails, the ballast is released, and the submarine then ascends to safety. - inside a modern cpu are features to prevent damage through overheating. in the event of cooling failure, the cpu will throttle then shut down beyond a critical temperature threshold to avoid damage. - in industrial automation, alarm signals are usually " normally closed " ( or active at 0 ). this insures that in case of a wire break the alarm will be triggered. if the signal were normally open, no wire failure would be detected. - in control systems, critically important signals can be carried by a complementary pair of wires ( < signal > and < not


in case of a wire break the alarm will be triggered. if the signal were normally open, no wire failure would be detected. - in control systems, critically important signals can be carried by a complementary pair of wires ( < signal > and < not _ signal > ). only states where the two signals are opposite ( one is high, the other low ) are valid. if both are high or both are low the control system knows that something is wrong with the sensor or connecting wiring. simple failure modes ( dead sensor, cut / unplugged wires ) are thereby detected. an example would be a control system reading both the no and nc poles of a spdt selector switch against common, and checking them for coherency before reacting to the input. - in hvac control systems, actuators that control dampers and valves may be fail - safe, for example, to prevent coils from freezing or rooms from overheating. older pneumatic actuators were inherently fail - safe since if the air pressure against the internal diaphragm failed, the built - in spring would push the actuator to its home position. newer electrical / electronic actuators need additional components ( springs or capacitors ) to automatically drive the actuator to home position upon loss of electrical power. as well as physical devices and systems fail - safe procedures can be created so that if a procedure is not carried out or carried out incorrectly no dangerous action results. for example : - in railway signalling signals which are not in active use for a train are required to be kept in the ' danger ' position. the default position of every signal is therefore " danger ", and therefore a positive action — setting signals to " clear " — is required before a train may pass. this practice also ensures that, in case of a fault in the signalling system, an incapacitated signalman, or the unexpected entry of a train, that a train will never be shown an erroneous " clear " signal. - train drivers are instructed that a railway signal showing a confusing, contradictory or unfamiliar aspect ( for example a colour light signal that has suffered an electrical failure and is showing no light at all ) must be treated as showing " danger ". in this way, the driver contributes to the fail - safety of the system. other terminology fail - safe ( foolproof ) devices are also known as poka - yoke devices. poka - yoke, a japanese term, was coined by shigeo shingo, a quality


the fail - safety of the system. other terminology fail - safe ( foolproof ) devices are also known as poka - yoke devices. poka - yoke, a japanese term, was coined by shigeo shingo, a quality expert. " safe to fail " refers to civil engineering designs such as the room for the river project in netherlands and the thames estuary 2100 plan which incorporate flexible adaptation strategies or climate change adaption which provide for, and limit damage, should extreme events such as 500 year floods occur. see also | look up fail - safe in wiktionary, the free dictionary. | - control theory - dead man ' s switch - elegant degradation - failing badly - fault - tolerant design - fault - tolerant system - iec 61508 ( safe failure fraction - sff ) - safe - life design - safety engineering - " fail - safe ". audioenglich. net. accessed 2009. 12. 31 - e. g., david b. rutherford, jr., " what do you mean — it ' s fail - safe? " : evaluating fail - safety in processor - based vital control systems. 1990 rapid transit conference - harris, tom. " how aircraft carriers work ". howstuffworks, inc. retrieved 2007 - 10 - 20. - " what is a unidirectional rotating bezel ". retrieved 9 may 2013. - manual on uniform traffic control devices, federal highway administration, 2003 - " when failure is not an option : the evolution of fail - safe actuators ". kmc controls. retrieved 10 may 2013. - shingo, shigeo ; andrew p. dillon ( 1989 ). a study of the toyota production system from an industrial engineering viewpoint. portland, oregon : productivity press. p. 22. isbn 0 - 915299 - 17 - 8. oclc 19740349 - john r. grout, brian t. downs. " a brief tutorial on mistake - proofing, poka - yoke, and zqc ", mistakeproofing. com - " thames estuary 2100 plan ". uk environment agency. november 2012. retrieved march 20, 2013. - " thames estuary 2100 ( te2100 ) ". uk environment agency. retrieved march 20, 2013. - jennifer weeks ( march 20, 2013 ). " adaptation expert paul kirshen proposes a new paradigm for civil engineers : ' safe to fail, ' not ' fail safe ' ". the daily climate. retrieved march 20


grant hall, the symbol of fort leavenworth and headquarters of the u. s. army combined arms center | controlled by | | u. s. army | | garrison | | u. s. army combined arms center command and general staff college 705th military police battalion | commanders | | ltg david g. perkins | fort leavenworth is a united states army facility located in leavenworth county, kansas, immediately north of the city of leavenworth in the upper northeast portion of the state. it is the oldest active united states army post west of washington, d. c., having been in operation for over 180 years. fort leavenworth has been historically known as the " intellectual center of the army ". fort leavenworth was also the origin of the buffalo soldiers who were originally members of the u. s. 10th cavalry regiment of the united states army, formed on 21 september 1866 at fort leavenworth, kansas. the nickname was given to the " negro cavalry " by the native american tribes they fought ; the term eventually became synonymous with all of the african - american regiments formed in 1866. during the country ' s westward expansion, fort leavenworth was a forward destination for thousands of soldiers, surveyors, immigrants, american indians, preachers and settlers who passed through. the garrison supports the united states army training and doctrine command ( tradoc ) by managing and maintaining the home of the united states army combined arms center ( cac ). cac ' s mission involves leader development, collective training, army doctrine and battle command ( current and future ). fort leavenworth is home to the military corrections complex, consisting of the united states disciplinary barracks, the department of defense ' s only maximum security prison, and the midwest joint regional correctional facility. in addition, the fort leavenworth garrison supports numerous tenant organizations that directly and indirectly relate to the functions of the cac, including the united states army command and general staff college and the foreign military studies office. the fort occupies 5, 600 ac ( 2, 300 ha ) and 7, 000, 000 ft² ( 700, 000 m² ) of space in 1, 000 buildings and 1, 500 quarters. it is located on the frontier military scenic byway ( u. s. route 69 and k - 7 corridor ), which was originally a military road connecting to fort scott national historic site and fort gibson. tenants and organization the garrison commander is a colonel reporting via imcom west to the installation management command. the fort claims to be the


and k - 7 corridor ), which was originally a military road connecting to fort scott national historic site and fort gibson. tenants and organization the garrison commander is a colonel reporting via imcom west to the installation management command. the fort claims to be the " intellectual center " of the army because much of its mission involves training. major tenants include : - united states army combined arms center ( cac ) which among its various responsibilities is the united states army command and general staff college, which includes a degrees granting graduate school for u. s. and allied soldiers and officers. the school trains almost all of the army ' s majors. all modern five - star army generals have passed through the college including george marshall, douglas macarthur, dwight eisenhower, henry “ hap ” arnold, and omar bradley. since 1978 it has been commanded by a lieutenant general ( 3 stars ). in 2007, its commander was david petraeus. it reports to the united states army training and doctrine command ( tradoc ). - united states disciplinary barracks, which is the only maximum security prison for military personnel of all branches. since a 2007 reorganization, its commander is a colonel who reports to the united states army corrections command. - midwest joint regional correctional facility, a low security prison. reports to the united states army corrections command. - foreign military studies office ( which reports to tradoc ) - munson army health center ( base hospital ) - university of foreign military and cultural studies ( which includes teaching red teams among its courses ) - sherman army airfield — the base airport ( which reports to the garrison ) - fort leavenworth national cemetery - tradoc analysis center ( which reports to tradoc ) - headquarters of the national guard ' s 35th infantry division ( mechanized ) - battle command training center is the focal point for national guard of the united states division and brigade staff training and development. - army / ace registry transcript systems ( handles transcripts for all its training ) the fort is 10 miles north of the 18th century french fort de cavagnal, which was the farthest west fort in louisiana ( new france ). its commandant was francois coulon de villiers, a brother to louis coulon de villiers, who was the only military commander to force george washington to surrender ( after revenging the murder of his half brother joseph coulon de jumonville while in washington ' s custody, which was the incident that set off the french and indian war ). the french abandoned the fort after ceding its territory to louisiana ( new spain


the murder of his half brother joseph coulon de jumonville while in washington ' s custody, which was the incident that set off the french and indian war ). the french abandoned the fort after ceding its territory to louisiana ( new spain ) at the conclusion of the french and indian war. the fort location had been chosen then because of its proximity to a large kansa tribe village. colonel henry leavenworth, with the officers and men of the 3rd infantry regiment from jefferson barracks at st. louis, missouri, established fort leavenworth in 1827 to be a forward base protecting the santa fe trail. leavenworth ' s instructions had been the following : colonel leavenworth of the 3d infantry, with four companies of his regiment will ascend the missouri and when he reaches a point on its left band near the mouth of little platte river and within a range of twenty miles above or below its confluence, he will select such position as in his judgment is best calculated for the site of a permanent cantonment. the spot being chosen, he will then construct with the troops of his command comfortable, though temporary quarters sufficient for the accommodation of four companies. this movement will be made as early as the convenience of the service will permit. leavenworth was to report that spot around the confluence on the east side of the missouri river ( near present day farley, missouri ) would be prone to flooding and on 8 may 1827 recommended the location 20 miles ( 32 km ) upstream on the west bank in the bluffs above the river. the first army installation in cantonment leavenworth ( its original name ) was located on scott avenue, south of the post chapel with initial strength of 14 officers and 174 enlisted men. the cantonment almost immediately increased in importance as it became the eastern terminus for the santa fe trail and oregon trail. after indian removal act of 1830 attempted to remove all indians west of the missouri - kansas border, the fort which is west of the border assumed even more importance. in 1832, it was renamed " fort leavenworth ". between 1832 and 1834, the rookery was built as bachelor officer quarters. the rookery is the oldest building in kansas and would be the office of the first territorial governor and thus the first capitol in kansas from 1854 to 1855 when the capitol was moved to pawnee, kansas. in 1836, william clark at the fort presided over the transfer of indian land directly across the missouri river from the fort to the u. s. government in the platte purchase which involved the entire northwest


the capitol was moved to pawnee, kansas. in 1836, william clark at the fort presided over the transfer of indian land directly across the missouri river from the fort to the u. s. government in the platte purchase which involved the entire northwest corner of missouri. in 1839, col. stephen w. kearny marched against the cherokees with 20 companies of dragoons, the largest u. s. mounted force ever assembled. throughout the mexican - american war, fort leavenworth was the outfitting post for the army of the west. during the 1850s, troops from ft. leavenworth were mobilized to control the " mormon problem " in what became known as the utah war. at the outbreak of the civil war, camp lincoln was established on post as a reception and training station for kansas volunteers. in 1864, news of the approach of confederate general sterling price prompted construction of fort sully, a series of earthworks for artillery emplacements on hancock hill, overlooking what is now the fort leavenworth national cemetery. ( see fort sully ( fort leavenworth ) ). however, price ' s forces never reached fort leavenworth, having met defeat at westport, which is now part of kansas city. during its long history, the post was never subject to enemy attack. for three decades following the war, the army ' s chief mission was control of the american indian tribes on the western plains. between 1865 and 1891, the army had more than 1, 000 combat engagements with apache, modoc, cheyenne, ute, nez perce, comanche, kiowa, kickapoo and other tribes. the fort leavenworth national cemetery is one of the national cemeteries established by abraham lincoln on 17 july 1862. veterans since the war of 1812 have been laid to rest in the cemetery. one veteran of the war of 1812 is the cemetery ' s most famous occupant, brigadier general henry leavenworth, who gave his name to the fort, the cemetery, and the town and county they are located in. others buried in the cemetery include 10 medal of honor recipients, seven confederate prisoners of war as well as soldiers killed in operation desert storm, operation iraqi freedom and operation enduring freedom. although there is no longer space for new burial sites, burials frequently take place for those who already have family members interred in the cemetery. reconstruction and indian wars in 1866, the u. s. congress authorized the formation of four black regiments, which were the 24th and 25th infantry regiments and the 9th and


, burials frequently take place for those who already have family members interred in the cemetery. reconstruction and indian wars in 1866, the u. s. congress authorized the formation of four black regiments, which were the 24th and 25th infantry regiments and the 9th and 10th cavalry regiments. the 10th cavalry regiment was formed at fort leavenworth under the command of col. benjamin h. grierson. today, a monument stands at fort leavenworth in tribute to the " buffalo soldier " of the 9th and 10th cavalry regiments. the fort ' s first catholic church was built in 1871 and was later replaced by st. ignatius chapel in 1889. st. ignatius chapel was destroyed by fire in december 2001. the first protestant chapel, memorial chapel, was built by prison labor in 1878 of stone quarried on post. the round window behind the chapel ' s front altar was intentionally installed slightly askew by an inmate who was angry at his work boss. this chapel has brass cannon embedded in the walls at the sides of the church, and photos of many of the officers involved in the early history of the fort, including some of the custer family. the western branch national military home ( " old soldiers ' home " ), now called the veterans medical center, or dwight d. eisenhower medical center historic district was established in 1885 as part of the national home for disabled volunteer soldiers system. the soldier home is closely associated with the nearby cemetery that became the fort leavenworth national cemetery in 1973. world war i was the first opportunity to evaluate the impact of sherman ' s school. graduates excelled in planning complex american expeditionary forces operations. by the end of the war, they dominated staffs throughout the aef. in the years between the world wars, graduates included such officers as dwight d. eisenhower, omar n. bradley and george s. patton. during world war ii, some 19, 000 officers completed various courses at fort leavenworth. by the end of 1943, commanders and staffs of 26 infantry, airborne and cavalry divisions had trained as teams at the school. general michael joe costello of the army of the newly formed irish free state attended fort leavenworth from 1926 to 1927, passing with such distinction that he was recommended for the united states army war college. in 1946, the school was given its current name. in 1959, the college moved to the newly built j. franklin bell hall on arsenal hill. in 1985, the harold k. johnson wing was added to house the combined arms and services staff school ( cas3 ). classes for the school


name. in 1959, the college moved to the newly built j. franklin bell hall on arsenal hill. in 1985, the harold k. johnson wing was added to house the combined arms and services staff school ( cas3 ). classes for the school of advanced military studies and the school for command preparation, as well as the combined arms research library, are located in eisenhower hall which was dedicated in 1994. until the early 1970s, a battery of four nike - hercules missiles were deployed at bell point on a hill on the west side of the fort. the base is served by the sherman army airfield which has a 5, 905 - foot ( 1, 800 m ) runway and operates under a joint agreement with the city of leavenworth, kansas that permits civilian aircraft to use it all hours. the airfield was inundated by the missouri river in levee breaches during the great flood of 1951, the great flood of 1993, and the great flood of 2011. freedom ' s frontier heritage area fort leavenworth is considered one of the most significant historic military installations in the department of the army, as well as to the nation. the fort ' s 5, 634 ac ( 2, 279 ha ) contain a 213 ac ( 86. 1 ha ) national historic landmark district ( nhld ), which was established in 1974. a number of historic preservation investigations have been conducted over the past few decades at fort leavenworth. in 1970, for example, two historic sites were listed on the national register of historic places ( nrhp ) : the main parade ground and the santa fe trail ruts. during 2006, this historic military site became part of a new freedom ' s frontier national heritage area. - " fort leavenworth history ". garrison. leavenworth. army. mil. retrieved 2012 - 03 - 19. - " combined arms center overview ". usacac. army. mil. 6 july 2011. retrieved 2012 - 03 - 19. - " fort leavenworth, ks • units / tenants ". garrison. leavenworth. army. mil. 6 october 2006. retrieved 2010 - 03 - 16. [ dead link ] - " college – command and general staff college foundation ". cgscfoundation. org. retrieved 2010 - 03 - 16. - h. r. 1177 : 5 - star generals commemorative coin act. coinnews. net, 23 february 2009. - " u. s. army tradoc analysis center ( trac ) ". trac. army.


. - h. r. 1177 : 5 - star generals commemorative coin act. coinnews. net, 23 february 2009. - " u. s. army tradoc analysis center ( trac ) ". trac. army. mil. 26 february 2010. retrieved 2010 - 03 - 16. - " the battle command training center ". bctc. army. mil. 29 december 2009. retrieved 2010 - 03 - 16. - " army / american council on education registry transcript system ( aarts ) home page ". aarts. army. mil. retrieved 2012 - 03 - 19. - fort de cavagnial : imperial france in kansas, 1744 – 1764 kclibrary. org. - [ the journals of the lewis and clark expedition, vol. 2., g. e. moulton, ed., univ. of nebraska press, 1986, pp. 323 – 333. - a brief history of fort leavenworth – john w. partin. - fort leavenworth – globalsecurity. org – retrieved march 6, 2008. - the capitals of kansas – retrieved march 6, 2008. - united states department of veterans affairs, " cemeteries – fort leavenworth national cemetery " at http : / / www. cem. va. gov / cem / cems / nchp / ftleavenworth. asp retrieved 15 october 2011 - fort leavenworth, ks • unknown. - " gen. edmund rice biography ". steven nitch. retrieved 7 april 2012. - " fort leavenworth ". national historic landmark summary listing. national park service. retrieved 2008 - 06 - 25. - jerry l. rogers and donald f. dosch ( 13 december 1973 ). national register of historic places inventory - nomination : fort leavenworth, national historic landmark / fort leavenworth ( pdf ). national park service. retrieved 2009 - 06 - 22 and pdf ( 2. 23 mb ) | wikimedia commons has media related to : fort leavenworth | - freedom ' s frontier - frontier army museum - fort leavenworth home page - guide for visitors to fort leavenworth - the fort leavenworth lamp online – fort leavenworth ' s newspaper - u. s. army combined arms center - u. s. army disciplinary barracks, fort leavenworth, kansas - tradoc schools - tradoc website - fort leavenworth history collection combined arms research library digital library - usd 207, local school district


irish house of lords | irish house of lords | arms of ireland | disbanded | | 31 december 1800 | | succeeded by | | house of lords of the united kingdom | | lord chancellor | | the earl of clare1 | voting system | | appointment by monarch or inheritance of seat | | lords chamber, irish houses of parliament, dublin | parliament of great britain the irish house of lords ( irish : teach na dtiarnai ) was the upper house of the parliament of ireland that existed from medieval times until 1800. it was abolished along with the irish house of commons by the act of union. the house of lords was presided over by the lord chancellor, who sat on the woolsack, a large seat stuffed with wool from each of the three lands of england, ireland and scotland. at the state opening of the irish parliament members of parliament were summoned to the house of lords from the house of commons chamber by black rod, a royal official who would " command the members on behalf of his excellency to attend him in the chamber of peers " sessions were formally opened by the speech from the throne by the lord lieutenant, who sat on the throne beneath a canopy of crimson velvet. the lords started as a group of barons in the lordship of ireland that was generally limited to the pale, a variable area around dublin subject to english law. they sat as a group, not as a separate house, from the first meeting of the irish parliament in 1297. from the establishment of the kingdom of ireland in 1542 the lords included a large number of new gaelic and norman lords under the policy of surrender and regrant. religious division was reflected in the house, but as late as the 1689 " patriot parliament " a majority of lords had remained roman catholics, while the administration and a slight majority in the commons were anglican. by 1632 the ( catholic ) lord baltimore established colonies in newfoundland and maryland. in 1634 the campaign to secure " the graces " came to a head. most of these catholic lords lost their titles in the ensuing 1641 rebellion, notably during the 1652 cromwellian settlement. these dispossessed lords were regranted their titles ( if not always their lands ) after the restoration of 1660 by the act of settlement 1662. others took the losing side in the williamite war in ireland ( 1689 - 91 ), and a much smaller number of them were re - granted their lands in the 18th century. by the 1790s most of the lords personified and wanted to protect the " protestant ascendancy ". by the time of its


jesse owens in 1936 | full name | | james cleveland owens | | born | | september 12, 1913 oakville, alabama, usa | died | | march 31, 1980 tucson, arizona, usa | height | | 5 ft 10 in ( 1. 78 m ) | | weight | | 165 lb ( 75 kg ) | | sport | | track and field athletics | | event ( s ) | | sprint, long jump | james cleveland " jesse " owens ( september 12, 1913 – march 31, 1980 ) was an american track and field athlete who specialized in the sprints and the long jump. he participated in the 1936 summer olympics in berlin, germany, where he achieved international fame by winning four gold medals : one each in the 100 meters, the 200 meters, the long jump, and as part of the 4x100 meter relay team. he was the most successful athlete at the 1936 summer olympics. owens was the youngest of ten children, three girls and seven boys, born to henry cleveland owens and mary emma fitzgerald in oakville, alabama on september 12, 1913. j. c., as he was called, was nine years old when the family moved to cleveland, ohio for better opportunities, as part of the great migration, when 1. 5 million african americans left the segregated south. when his new teacher asked his name ( to enter in her roll book ), he said " j. c. ", but because of his strong southern accent, she thought he said " jesse ". the name took, and he was known as jesse owens for the rest of his life. as a boy and youth, owens took different jobs in his spare time : he delivered groceries, loaded freight cars and worked in a shoe repair shop while his father and older brother worked at a steel mill. during this period, owens realized that he had a passion for running. throughout his life, owens attributed the success of his athletic career to the encouragement of charles riley, his junior high track coach at fairmount junior high school. since owens worked in a shoe repair shop after school, riley allowed him to practice before school instead. owens first came to national attention when he was a student of east technical high school in cleveland ; he equalled the world record of 9. 4 seconds in the 100 - yard ( 91 m ) dash and long - jumped 24 feet 9 1⁄2 inches ( 7. 56 metres ) at the 1933 national high school championship in chicago. ohio state university owens attended ohio state university after employment was found for his father, ensuring


yard ( 91 m ) dash and long - jumped 24 feet 9 1⁄2 inches ( 7. 56 metres ) at the 1933 national high school championship in chicago. ohio state university owens attended ohio state university after employment was found for his father, ensuring the family could be supported. affectionately known as the " buckeye bullet, " owens won a record eight individual ncaa championships, four each in 1935 and 1936. ( the record of four gold medals at the ncaa was equaled only by xavier carter in 2006, although his many titles also included relay medals. ) though owens enjoyed athletic success, he had to live off campus with other african - american athletes. when he traveled with the team, owens was restricted to ordering carry - out or eating at " black - only " restaurants. similarly, he had to stay at " blacks - only " hotels. owens did not receive a scholarship for his efforts, so he continued to work part - time jobs to pay for school. owens ' s greatest achievement came in a span of 45 minutes on may 25, 1935, during the big ten meet at ferry field in ann arbor, michigan, where he set three world records and tied a fourth. he equaled the world record for the 100 yard dash ( 9. 4 seconds ) ; and set world records in the long jump ( 26 ft 8 1⁄4 in or 8. 13 m, a world record that would last 25 years ) ; 220 - yard ( 201. 2 m ) sprint ( 20. 3 seconds ) ; and 220 - yard ( 201. 2m ) low hurdles ( 22. 6 seconds, becoming the first to break 23 seconds ). in 2005, university of central florida professor of sports history richard c. crepeau chose these wins on one day as the most impressive athletic achievement since 1850. in 1936, owens arrived in berlin to compete for the united states in the summer olympics. adolf hitler was using the games to show the world a resurgent nazi germany. he and other government officials had high hopes that german athletes would dominate the games with victories ( the german athletes achieved a " top of the table " medal haul ). meanwhile, nazi propaganda promoted concepts of " aryan racial superiority " and depicted ethnic africans as inferior. owens surprised many by winning four gold medals : on august 3, 1936, he won the 100m sprint, defeating ralph metcalfe ; on august 4, the long jump ( later crediting friendly and helpful advice from luz long, the german competitor he ultimately defeated ) ; on august 5, the 200m sprint


1936, he won the 100m sprint, defeating ralph metcalfe ; on august 4, the long jump ( later crediting friendly and helpful advice from luz long, the german competitor he ultimately defeated ) ; on august 5, the 200m sprint ; and, after he and ralph metcalfe were added to the 4 x 100 m relay team that featured frank wykoff and foy draper, following a request by the germans for united states coach dean cromwell to replace jewish - american sprinters marty glickman and sam stoller, he won his fourth on august 9 ( a performance not equaled until carl lewis won gold medals in the same events at the soviet boycotted 1984 summer olympics ). jesse owens set the world record in the long jump in 1935, and this record would stand for 25 years ( a very rare length of time for a track and field record ), until it was finally broken by ralph boston in 1960. in an ironic coincidence, owens was a spectator at the 1960 summer olympics when boston took the gold medal in the long jump. just before the competitions, owens was visited in the olympic village by adi dassler, the founder of the adidas athletic shoe company. he persuaded owens to use gebruder dassler schuhfabrik shoes, the first sponsorship for a male african - american athlete. on the first day, hitler shook hands only with the german victors and then left the stadium. olympic committee officials insisted hitler greet every medalist or none at all. hitler opted for the latter and skipped all further medal presentations. on reports that hitler had deliberately avoided acknowledging his victories, and had refused to shake his hand, owens said at the time : " hitler had a certain time to come to the stadium and a certain time to leave. " " it happened he had to leave before the victory ceremony after the 100 meters. but before he left i was on my way to a broadcast and passed near his box. he waved at me and i waved back. i think it was bad taste to criticize the ' man of the hour ' in another country. " owens was allowed to travel with and stay in the same hotels in germany as whites, while at the time african americans in many parts of the united states had to stay in segregated hotels while traveling. after a new york city ticker - tape parade of fifth avenue in his honor, owens had to ride the freight elevator at the waldorf - astoria to reach the reception honoring him. fdr never invited jesse owens to the white house following his


. after a new york city ticker - tape parade of fifth avenue in his honor, owens had to ride the freight elevator at the waldorf - astoria to reach the reception honoring him. fdr never invited jesse owens to the white house following his triumphs at the olympics games. since 1936 was a presidential - election year, roosevelt was afraid that he would lose southern votes if he played kowtow to a black man. jesse owns also publicly endorsed alf landon during the upcoming election. " hitler didn ' t snub me – it was fdr who snubbed me. the president didn ' t even send me a telegram. " hitler sent owens a commemorative inscribed cabinet photograph of himself. jesse owens was never invited to the white house nor were honors bestowed upon him by president franklin d. roosevelt ( fdr ) or his successor harry s. truman during their terms. in 1955, president dwight d. eisenhower ( himself an athlete of note ) honored owens by naming him an " ambassador of sports. " the dormitory used by owens during the olympics has been fully restored into a living museum, with pictures of his accomplishments at the games, and a letter ( intercepted by the gestapo ) from a fan urging him not to shake hands with hitler. after the games had finished, the olympic team and owens were all invited to compete in sweden. he decided to capitalize on his success by returning to the united states to take up some of the more lucrative commercial offers. united states athletic officials were furious and withdrew his amateur status, ending his career immediately. owens was angry, saying, " a fellow desires something for himself. " prohibited from amateur sporting appearances to bolster his profile, owens found the commercial offers all but disappeared. in 1946, he joined abe saperstein in the formation of the west coast baseball association ( wcba ), a new negro baseball league ; owens was vice - president and the owner of the portland ( oregon ) rosebuds franchise. he toured with the rosebuds, sometimes entertaining the audience in between doubleheader games by competing in races against horses. the wcba disbanded after only two months. owens helped promote the exploitation film mom and dad in black neighborhoods. he tried to make a living as a sports promoter, essentially an entertainer. he would give local sprinters a ten - or twenty - yard start and beat them in the 100 - yd ( 91 - m ) dash. he also challenged and defeated racehorses ; as he revealed later, the trick was to race a high - strung thoroughbred that would be


cancer on and off beginning in december 1979. he died in tucson, arizona, on march 31, 1980, with his wife and other family members at his bedside. he is buried in oak woods cemetery in chicago. awards, tributes and honors - in 1936, four english oak saplings, one for each olympic gold medal, from the german olympic committee. one of the trees was planted at the university of southern california, one at rhodes high school in cleveland, oh where he trained, and one is rumored to be located on the ohio state university campus, but has yet to be identified. the fourth tree was located at the home of jess owens ' mother, but was removed when the house was demolished. - in 1970, owens was inducted to the alabama sports hall of fame. - in 1976 he was awarded the presidential medal of freedom by president gerald ford. - in 1976, he was made part of the olympic order for his fight against racism in the 1936 olympics in berlin. - in 1980, a new asteroid was discovered by antonin mrkos at klet observatory which was named as 6758 jesseowens in honor of jesse owens. - usa track and field created the jesse owens award in 1981, which is given annually to the country ' s top track and field athlete. - in 1984, an emmy award - winning biographical television film of his life, the jesse owens story, was released, with dorian harewood portraying owens. - in 1984 a street near the olympic stadium in berlin was renamed jesse - owens - allee, and the jesse owens realschule / oberschule ( a secondary school ) in berlin - lichtenberg, was named for him. - in 1988, he was portrayed in king of the olympics : the lives and loves of avery brundage by ronnie britton. - on march 28, 1990, owens was posthumously awarded the congressional gold medal by president george h. w. bush. - two u. s. postage stamps have been issued to honor owens, one in 1990 and another in 1998. - in 1996, owens ' s hometown of oakville, alabama, dedicated jesse owens memorial park in his honor, at the same time that the olympic torch came through the community, 60 years after his olympic triumph. an article in the wall street journal of june 7, 1996, covered the event and included this inscription written by poet charles ghigna that appears on a bronze plaque at the park : - may this light shine forever - as a symbol to all who run - for the freedom of sport,


june 7, 1996, covered the event and included this inscription written by poet charles ghigna that appears on a bronze plaque at the park : - may this light shine forever - as a symbol to all who run - for the freedom of sport, - for the spirit of humanity, - for the memory of jesse owens. - in 2001, the ohio state university dedicated jesse owens memorial stadium for track and field events. the campus also houses three recreational centers for students and staff named in his honor. - in 2002, scholar molefi kete asante listed jesse owens on his list of 100 greatest african americans. - in cleveland, ohio, a statue of owens in his ohio state track suit was installed at fort huntington park, west of the old courthouse. - phoenix, arizona named the jesse owens medical plaza in his honor, as well as jesse owens parkway. - in markus zusak ' s 2006 hit, the book thief, a character named rudy steiner covers himself with charcoal and runs 100 meters at the local sporting field. this was known around rudy ' s neighborhood as the " jesse owens " incident. later in the book when he dies, protagonist liesel meminger calls him " jesse owens " in her attempts to revive him. - jesse owens park, located in tucson, arizona, is a staple of local youth athletics there. - at the 2009 world athletic championships in berlin, all members of the united states track & field team wore badges with " jo " to commemorate owens ' s victories in the same stadium 73 years before. - in early 2010, the ohio historical society proposed jesse owens as a finalist from a statewide vote for inclusion in statuary hall at the united states capitol. - on monday, november 15, 2010, the city of cleveland renamed east roadway, between rockwell and superior avenues in public square, jesse owens way, in hopes that it will keep the great jesse owens on the minds of all sports fans. - a novel in french written by lebanese novelist alexandre najjar, berlin 36, plon ( publisher ), paris, 2009, tells the story of owens, particularly during the berlin olympic games. najjar visited chicago, ohio and alabama to achieve this distinguished tribute to owens. - for his contribution to sports in los angeles, he was honored with a los angeles memorial coliseum " court of honor " plaque by the coliseum commissioners. - in the london 2012 summer olympics opening ceremony, just after the olympic cauldron had been lit, the 80, 000 individual pixels in the audience seating area were used as a


angeles memorial coliseum " court of honor " plaque by the coliseum commissioners. - in the london 2012 summer olympics opening ceremony, just after the olympic cauldron had been lit, the 80, 000 individual pixels in the audience seating area were used as a giant video screen to show footage of owens running around the stadium. - baker, william j. jesse owens – an american life, p. 19. - "? ". archived from the original on july 3, 2007. retrieved april 5, 2008. - " jesse owens : track & field legend : biography ". archived from the original on december 23, 2007. retrieved january 6, 2008. - schwartz, larry ( 2007 ). " owens pierced a myth ". - rose, lacey ( november 18, 2005 ). " the single greatest athletic achievement ". forbes. com. - bachrach, susan d. the nazi olympics : berlin 1936. isbn 0 - 316 - 07087 - 4. - " jesse owens, 1913 – 1980 : he was once the world ' s fastest runner ". voice of america. december 20, 2008. retrieved december 22, 2008. - pbs : american experience. jessie owens. ( accessed : may 2, 2012 ) - " how adidas and puma were born ". in. rediff. com. november 8, 2005. retrieved june 15, 2010. - hyde flippo, the 1936 berlin olympics : hitler and jesse owens, german myth 10, german. about. com - rick shenkman, adolf hitler, jesse owens and the olympics myth of 1936 february 13, 2002 from history news network ( article excerpted from rick shenkman ' s legends, lies and cherished myths of american history, william morrow & co, 1988 isbn 0 - 688 - 06580 - 5 ) - owens arrives with kind words for all officials – the pittsburgh press, 24 august 1936. news. google. co. uk. retrieved on 2011 - 09 - 15. - albert speer ( 2009 ). inside the third reich. phoenix. p. 119. isbn 978 - 1842127353. - schaap, jeremy ( 2007 ). triumph : the untold story of jesse owens and hitler ' s olympics. new york : houghton mifflin harcourt. isbn 978 - 0 - 618 - 68822 - 7. - owens weighs his pro offers – the baltimore sun, august 18, 1936. pqasb. pqarchiver. com ( 1936 - 08 - 18 ). retrieved on


isbn 978 - 0 - 618 - 68822 - 7. - owens weighs his pro offers – the baltimore sun, august 18, 1936. pqasb. pqarchiver. com ( 1936 - 08 - 18 ). retrieved on 2011 - 09 - 15. - " hitler ’ s olympic village faces conservation battle ". voice of america. august 26, 2012. - altman, alex ( august 18, 2009 ). " usain bolt : the world ' s fastest human ". time. retrieved june 15, 2010. - thinkexist. com quotations. " jesse owens quotes ". thinkexist. com. retrieved june 15, 2010. - riley, liam. " bbc – an emperor among professionals ". bbc. retrieved may 17, 2011. - " west coast baseball association ". organizing black america : an encyclopedia of african american associations. bookrags. 2005 – 02 – 10. retrieved july 31, 2010. - simonich, milan ( july 12, 2010 ). " sun city home to the negro leagues for one weekend ". hidden el paso. el paso times. retrieved july 31, 2010. - schwartz, larry. " owens pierced a myth ". espn. retrieved april 30, 2009. - " jesse owens is fined in tax case ". the times - news. united press international. february 2, 1966. retrieved august 10, 2011. - " jesse owens : olympic legend - quotes ". retrieved may 8, 2009. - the owens family. library. osu. edu - " jesse owens ' s biographical information ". whitehouse. gov. retrieved june 15, 2010. - http : / / www. nytimes. com / learning / general / onthisday / bday / 0912. html jesse owens dies of cancer at 66 : hero of the 1936 berlin olympics - http : / / www. dispatch. com / content / blogs / a - look - back / 2011 / 10 / did - jesse - owens - plant - a - tree - at - osu. html did jesse owens plant a tree at osu? - the colombus dispatch, october 07, 2011 - " get caught ". ohio state recreational sports. retrieved august 31, 2010. - asante, molefi kete ( 2002 ). 100 greatest african americans : a biographical encyclopedia. amherst, new york. prometheus books. isbn 1 - 57392 - 963 - 8. - soul of cleveland website last retrieved 1 / 31 /


molefi kete ( 2002 ). 100 greatest african americans : a biographical encyclopedia. amherst, new york. prometheus books. isbn 1 - 57392 - 963 - 8. - soul of cleveland website last retrieved 1 / 31 / 2009. - " 12th iaaf world championships in athletics – berlin 2009 – owens and long families to meet at owens exhibition in berlin ". berlin. iaaf. org. retrieved june 15, 2010. - blogs - yahoo! news. news. yahoo. com. retrieved on 2011 - 09 - 15. - danny boyle and frank cottrell boyce, the director and writer of the ceremony, in their audio commentary track to the bbc dvd of the entire opening ceremony | wikiquote has a collection of quotations related to : jesse owens | | wikimedia commons has media related to : jesse owens | - official website - jesse owens - an american experience documentary - obituary, new york times, april 1, 1980 - jesse owens memorial at find a grave - jesse owens museum - jesse owens information - jesse at the internet movie database - official " jesse owens movie " website - owens ' s accomplishments and encounter with adolf hitler ( espn ) - jesse owens video newsreel - jesse owens video in riefenstahl ' s olympia ( 1936 ) - jesse owens ' s u. s. olympic team bio - path of the olympic torch to owens ' s birthplace in north alabama - jesse owens article, encyclopedia of alabama


object pool pattern | | this article has an unclear citation style. ( march 2012 ) | the object pool pattern is a software creational design pattern that uses a set of initialized objects kept ready to use, rather than allocating and destroying them on demand. a client of the pool will request an object from the pool and perform operations on the returned object. when the client has finished, it returns the object, which is a specific type of factory object, to the pool rather than destroying it. object pooling can offer a significant performance boost in situations where the cost of initializing a class instance is high, the rate of instantiation of a class is high, and the number of instances in use at any one time is low. the pooled object is obtained in predictable time when creation of the new objects ( especially over network ) may take variable time. however these benefits are mostly true for objects that are expensive with respect to time, such as database connections, socket connections, threads and large graphic objects like fonts or bitmaps. in certain situations, simple object pooling ( that hold no external resources, but only occupy memory ) may not be efficient and could decrease performance. handling of empty pools object pools employ one of three strategies to handle a request when there are no spare objects in the pool. - fail to provide an object ( and return an error to the client ). - allocate a new object, thus increasing the size of the pool. pools that do this usually allow you to set the high water mark ( the maximum number of objects ever used ). - in a multithreaded environment, a pool may block the client until another thread returns an object to the pool. when writing an object pool, the programmer has to be careful to make sure the state of the objects returned to the pool is reset back to a sensible state for the next use of the object. if this is not observed, the object will often be in some state that was unexpected by the client program and may cause the client program to fail. the pool is responsible for resetting the objects, not the clients. object pools full of objects with dangerously stale state are sometimes called object cesspools and regarded as an anti - pattern. the presence of stale state is not always an issue ; it becomes dangerous when the presence of stale state causes the object to behave differently. for example, an object that represents authentication details may break if the " successfully authenticated " flag is not reset before it is passed out, since it will indicate that


; it becomes dangerous when the presence of stale state causes the object to behave differently. for example, an object that represents authentication details may break if the " successfully authenticated " flag is not reset before it is passed out, since it will indicate that a user is correctly authenticated ( possibly as someone else ) when they haven ' t yet attempted to authenticate. however, it will work just fine if you fail to reset some value only used for debugging, such as the identity of the last authentication server used. inadequate resetting of objects may also cause an information leak. if an object contains confidential data ( e. g. a user ' s credit card numbers ) that isn ' t cleared before the object is passed to a new client, a malicious or buggy client may disclose the data to an unauthorized party. if the pool is used by multiple threads, it may need the means to prevent parallel threads from grabbing and trying to reuse the same object in parallel. this is not necessary if the pooled objects are immutable or otherwise thread - safe. some publications do not recommend using object pooling with certain languages, such as java, especially for objects that only use memory and hold no external resources. opponents usually say that object allocation is relatively fast in modern languages with garbage collectors ; while the operator new needs only ten instructions, the classic delete pair found in pooling designs requires hundreds of them as it does more complex work. also, most garbage collectors scan " live " object references, and not the memory that these objects use for their content. this means that any number of " dead " objects without references can be discarded with little cost. in contrast, keeping a large number of " live " but unused objects increases the duration of garbage collection. in some cases, programs that use garbage collection instead of directly managing memory may run faster. in the. net base class library there are a few objects that implement this pattern. system. threading. threadpool is configured to have a predefined number of threads to allocate. when the threads are returned, they are available for another computation. thus, one can use threads without paying the cost of creation and disposal of threads. java supports thread pooling via java. util. concurrent. executorservice and other related classes. the executor service has a certain number of " basic " threads that are never discarded. if all threads are busy, the service allocates the allowed number of extra threads that are later discarded if


##rvice and other related classes. the executor service has a certain number of " basic " threads that are never discarded. if all threads are busy, the service allocates the allowed number of extra threads that are later discarded if not used for the certain expiration time. if no more threads are allowed, the tasks can be placed in the queue. finally, if this queue may get too long, it can be configured to suspend the requesting thread. see also - goetz, brian ( 2005 - 09 - 27 ). " java theory and practice : urban performance legends, revisited ". ibm developerworks. archived from the original on 2005 - 09 - 27. retrieved 2012 - 08 - 28. - goetz, brian ( 2005 - 09 - 27 ). " java theory and practice : garbage collection in the hotspot jvm ". ibm developerworks. archived from the original on 2003 - 11 - 25. retrieved 2012 - 08 - 28. - kircher, michael ; prashant jain ; ( 2002 - 07 - 04 ). " pooling pattern ". europlop 2002. germany. retrieved 2007 - 06 - 09. - oodesign article - improving performance with object pooling ( microsoft developer network ) - developer. com article - portland pattern repository entry - apache commons pool : a mini - framework to correctly implement object pooling in java - game programming patterns : object pool


ping ( networking utility ) | | this article needs additional citations for verification. ( december 2011 ) | ping is a computer network administration utility used to test the reachability of a host on an internet protocol ( ip ) network and to measure the round - trip time for messages sent from the originating host to a destination computer. the name comes from active sonar terminology which sends a pulse of sound and listens for the echo to detect objects underwater. ping operates by sending internet control message protocol ( icmp ) echo request packets to the target host and waiting for an icmp response. in the process it measures the time from transmission to reception ( round - trip time ) and records any packet loss. the results of the test are printed in the form of a statistical summary of the response packets received, including the minimum, maximum, and the mean round - trip times, and sometimes the standard deviation of the mean. ping does not evaluate or compute the time to establish the connection ; it only gives the mean round - trip times of an established connection with an open session. depending on the implementation, the ping command can be run with various command line switches to enable special operational modes. example options include : specifying the packet size used as the probe, automatic repeated operation for sending a specified count of probes, and time stamping. the ping or packet internet groper utility was authored by mike muuss in december 1983 as a tool to troubleshoot problems in an ip network. he named it after the sound that sonar makes, since its methodology is similar to sonar ' s echo location. | bit 0 - 7 | | bit 8 - 15 | | bit 16 - 23 | | bit 24 - 31 | | version / ihl | | type of service | | length | | identification | | flags and offset | | time to live ( ttl ) | | protocol | | checksum | | source ip address | | destination ip address | | type of message | | code | | checksum | generic composition of an icmp 32 - byte packet - ip header ( in blue ) : - protocol set to 1 ( icmp ) and type of service set to 0. - icmp header ( in red ) : - type of icmp message ( 8 bits ) - code ( 8 bits ) - checksum ( 16 bits ), calculated with the icmp part of the packet ( the header is not used ). it is the 16 - bit one ' s complement of the one ' s complement sum of the icmp message starting with the type field


a standard deviation of 0. 187 ms. the echo request ( " ping " ) is an icmp message whose data is expected to be received back in an echo reply ( " pong " ). the host must respond to all echo requests with an echo reply containing the exact data received in the request message. | type = 8 | | code = 0 | | header checksum | - the identifier and sequence number can be used by the client to match the reply with the request that caused the reply. in practice, most linux systems use a unique identifier for every ping process, and sequence number is an increasing number within that process. windows uses a fixed identifier, which varies between windows versions, and a sequence number that is only reset at boot time. - the data received in the echo request must be entirely included in the echo reply. the echo reply ( " pong " ) is an icmp message generated in response to an echo request, and is mandatory for all hosts and routers. | type = 0 | | code = 0 | | header checksum | - type and code must be set to 0. - the identifier and sequence number can be used by the client to determine which echo requests are associated with the echo replies. - the data received in the echo request must be entirely included in the echo reply. possible reply messages include! h,! n, or! p ( host, network or protocol unreachable )! s ( source route failed )! f ( fragmentation needed )! u or! w ( destination network / host unknown )! i ( source host is isolated )! a ( communication with destination network administratively prohibited )! z ( communication with destination host administratively prohibited )! q ( for this tos the destination network is unreachable )! t ( for this tos the destination host is unreachable )! x ( communication administratively prohibited )! v ( host precedence violation )! c ( precedence cutoff in effect )! < num > ( icmp unreachable code < num > ) in case of error, destination host or intermediate router will send back an icmp error message, i. e. host unreachable or ttl exceeded in transit. in addition these messages include the first 8 bytes of original message ( in this case header of icmp echo request, including quench value ), so ping utility can match it to originating query. 16 : 24 : 47. 966461 ip (


addition these messages include the first 8 bytes of original message ( in this case header of icmp echo request, including quench value ), so ping utility can match it to originating query. 16 : 24 : 47. 966461 ip ( tos 0x0, ttl 128, id 15103, offset 0, flags [ none ], proto : icmp ( 1 ), length : 60 ) 192. 168. 146. 22 > 192. 168. 144. 5 : icmp echo request, id 1, seq 38, length 40 0x0000 : 4500 003c 3aff 0000 8001 5c55 c0a8 9216 e.. < :..... \ u.... 0x0010 : c0a8 9005 0800 4d35 0001 0026 6162 6364...... m5... & abcd 0x0020 : 6566 6768 696a 6b6c 6d6e 6f70 7172 7374 efghijklmnopqrst 0x0030 : 7576 7761 6263 6465 6667 6869 uvwabcdefghi the payload includes a timestamp of when the message was sent, as well a sequence number. this allows ping to compute the round trip time in a stateless manner without needing to record when packets were sent. in cases of no answer and no error message, most implementations of ping display nothing, or periodically print notifications about timing out. other types of pinging | | this section needs additional citations for verification. ( july 2011 ) | the term ping is commonly used to describe the transmission of any message or signal for the purpose of locating or testing network services or features. for example, a ping may be sent using the user datagram protocol ( udp ) to a device located behind a network address translator ( nat ) to keep the port binding on the nat from timing out and removing the mapping. other examples are short or empty instant messages, emails, voice mails, or missed - call notification to indicate availability. in various network multi - player games, a video game ping performs a similar function as the ping program for internet traffic. the game server measures the time required for a game packet to reach a client and a response to be received. this round - trip time is usually reported as the player ' s ping. it is an effective


function as the ping program for internet traffic. the game server measures the time required for a game packet to reach a client and a response to be received. this round - trip time is usually reported as the player ' s ping. it is an effective measurement of the player ' s latency, with lower ping times being desirable. this style of ping typically does not use icmp packets. - list of dos commands - list of unix utilities - ping of death - ping - pong scheme - smurf attack - mike muuss. " the story of the ping program ". adelphi, md, usa : u. s. army research laboratory. archived from the original on 8 september 2010. retrieved 8 september 2010. " i named it after the sound that a sonar makes, inspired by the whole principle of echo - location. " - salus, peter ( 1994 ). a quarter century of unix. addison - wesley. isbn 0 - 201 - 54777 - 5. - " rfc 1122 - requirements for internet hosts - - communication layers ". p. 42. retrieved 2012 - 03 - 19. " every host must implement an icmp echo server function that receives echo requests and sends corresponding echo replies. " - " shields up, firewall test. you get a warning about the dangers of ping if your computer answers ping request ". retrieved 4 june 2010. - rfc 792 - " rfc sourcebook ' s page on icmp ". retrieved 20 december 2010. - linux administration and privileged commands manual ( dead link ) : send icmp echo _ request to network hosts – - what is ping detailed explanation of icmp ping and command examples. - check what hosts on a network are active using ping use ping to find active hosts on your network. - online ping check from multiple locations : locations in netherlands, hong kong, usa, croatia, uk, ukraine, malaysia, russia, india, turkey.


this article is about the municipality in norway. for the community in minnesota, see rollag, minnesota rollag is a municipality in buskerud county, norway. it is part of the traditional region of numedal. the municipality of rollag was established on 1 january 1838 ( see formannskapsdistrikt ). nore og uvdal was separated from rollag in 1858. the administrative centre of the municipality is the village of rollag, although the most populated area in the municipality is veggli. rollag is bordered in the north by nore og uvdal, in the east by sigdal, in the south by flesberg, and in the west by tinn ( telemark county ). general information the municipality ( originally the parish ) is named after the old rollag farm ( old norse : roll ( u ) lag ), since the first church was built here. the first element is probably ( the genitive case of ) a river name rolla ( now called the troelva river ) and the last element is lag which means " fishing place ". the meaning of the river name is unknown ( maybe " the shivering " ). the coat - of - arms is from modern times. they were granted in 1993. the arms show two gold - colored lines on a red background. the lines represent an old warning cairn made of timber. the municipality lies in the heart of the numedal traditional region and valley, the westernmost valley in southeastern norway. the river numedalslagen flows through rollag and into the ytre oslofjord at larvik. in the northwest of the rollag lie the vegglifjell mountains, which are an entryway into the hardangervidda. the municipality ' s highest point is storegrønut at 1, 289 metres ( 4, 229 ft ) located in the vegglifjell mountains. rollag stave church - the rollag stave church ( built around 1150 - 1200 ) is located a few kilometres north of the centre of rollag. it was extended and windows were added in 1652. a new apse was added in 1666. the transept was constructed in 1697 - 1698. a gallery was added in 1702. the sacristy was built in 1739. a baroque pulpit was added in 1763. sister cities the following cities are twinned with rollag : external links


titan in natural color. the thick atmosphere is orange due to a dense organonitrogen haze. | discovered by | | christiaan huygens | | discovery date | | march 25, 1655 | | alternative names | | saturn vi | | semi - major axis | | 1, 221, 870 km | | orbital period | | 15. 945 d | | inclination | | 0. 34854 ° ( to saturn ' s equator ) | | mean radius | | 2, 576±2 km ( 0. 404 earths ) ( 1. 480 moons ) | | surface area | | 8. 3×107 km2 | | volume | | 7. 16×1010 km3 ( 0. 066 earths ) ( 3. 3 moons ) | | mass | | 1. 3452±0. 0002×1023 kg ( 0. 0225 earths ) ( 1. 829 moons ) | | mean density | | 1. 8798±0. 0044 g / cm3 | | equatorial surface gravity | | 1. 352 m / s2 ( 0. 14 g ) ( 0. 85 moons ) | | escape velocity | | 2. 639 km / s ( 1. 11 moons ) | | temperature | | 93. 7 k ( −179. 5 °c ) | | apparent magnitude | | 8. 2 to 9. 0 | | surface pressure | | 146. 7 kpa | 98. 4 % nitrogen ( n2 ), 1. 4 % methane ( ch4 ) ; 95 % n2, 4. 9 % ch4 titan ( or saturn vi ) is the largest moon of saturn. it is the only natural satellite known to have a dense atmosphere, and the only object other than earth for which clear evidence of stable bodies of surface liquid has been found. titan is the sixth ellipsoidal moon from saturn. frequently described as a planet - like moon, titan has a diameter roughly 50 % larger than the moon and is 80 % more massive. it is the second - largest moon in the solar system, after jupiter ' s moon ganymede, and is larger by volume than the smallest planet, mercury, although only about 41 % as massive. titan was the first known moon of saturn, discovered in 1655 by the dutch astronomer christiaan huygens, and was the fifth moon of a planet apart from the earth to be discovered. titan is primarily composed of water ice and rocky material. much as with venus prior to the


of saturn, discovered in 1655 by the dutch astronomer christiaan huygens, and was the fifth moon of a planet apart from the earth to be discovered. titan is primarily composed of water ice and rocky material. much as with venus prior to the space age, the dense, opaque atmosphere prevented understanding of titan ' s surface until new information accumulated with the arrival of the cassini – huygens mission in 2004, including the discovery of liquid hydrocarbon lakes in the satellite ' s polar regions. the surface is geologically young ; although mountains and several possible cryovolcanoes have been discovered, it is smooth and few impact craters have been found. the atmosphere of titan is largely composed of nitrogen ; minor components lead to the formation of methane and ethane clouds and nitrogen - rich organic smog. the climate — including wind and rain — creates surface features similar to those of earth, such as dunes, rivers, lakes and seas ( probably of liquid methane and ethane ), and deltas, and is dominated by seasonal weather patterns as on earth. with its liquids ( both surface and subsurface ) and robust nitrogen atmosphere, titan ' s methane cycle is viewed as an analog to earth ' s water cycle, although at a much lower temperature. discovery and naming titan was discovered on march 25, 1655, by the dutch astronomer / physicist christiaan huygens. huygens was inspired by galileo ' s discovery of jupiter ' s four largest moons in 1610 and his improvements in telescope technology. christiaan, with the help of his brother constantijn huygens, jr., began building telescopes around 1650. christiaan huygens discovered this first observed moon orbiting saturn with the first telescope they built. he named it simply saturni luna ( or luna saturni, latin for " saturn ' s moon " ), publishing in the 1655 tract de saturni luna observatio nova. after giovanni domenico cassini published his discoveries of four more moons of saturn between 1673 and 1686, astronomers fell into the habit of referring to these and titan as saturn i through v ( with titan then in fourth position ). other early epithets for titan include " saturn ' s ordinary satellite ". titan is officially numbered saturn vi because after the 1789 discoveries the numbering scheme was frozen to avoid causing any more confusion ( titan having borne the numbers ii and iv as well as vi ). numerous small moons have been discovered closer to saturn since then. the name titan, and the names of all seven satellites of saturn then known, came


to avoid causing any more confusion ( titan having borne the numbers ii and iv as well as vi ). numerous small moons have been discovered closer to saturn since then. the name titan, and the names of all seven satellites of saturn then known, came from john herschel ( son of william herschel, discoverer of mimas and enceladus ) in his 1847 publication results of astronomical observations made at the cape of good hope. he suggested the names of the mythological titans ( ancient greek : τιταν ), sisters and brothers of cronus, the greek saturn. in greek mythology, the titans were a race of powerful deities, descendants of gaia and uranus, that ruled during the legendary golden age. orbit and rotation titan orbits saturn once every 15 days and 22 hours. like many of the other satellites of the gas giants and the moon, its rotational period is identical to its orbital period ; titan is thus tidally locked in synchronous rotation with saturn, and always shows one face to the planet. because of this, there is a sub - saturnian point on its surface, from which the planet would appear to hang directly overhead. longitudes on titan are measured westward from the meridian passing through this point. its orbital eccentricity is 0. 0288, and the orbital plane is inclined 0. 348 degrees relative to the saturnian equator. viewed from earth, titan reaches an angular distance of about 20 saturn radii ( just over 1. 2 million km ) from saturn and subtends a disk 0. 8 arcseconds in diameter. the small, irregularly shaped satellite hyperion is locked in a 3 : 4 orbital resonance with titan. a " slow and smooth " evolution of the resonance — in which hyperion would have migrated from a chaotic orbit — is considered unlikely, based on models. hyperion probably formed in a stable orbital island, while the massive titan absorbed or ejected bodies that made close approaches. titan is 5, 150 km across, compared to 4, 879 km for the planet mercury, 3, 474 km for the moon, and 12, 742 km for the earth. before the arrival of voyager 1 in 1980, titan was thought to be slightly larger than ganymede ( diameter 5, 262 km ) and thus the largest moon in the solar system ; this was an overestimation caused by titan ' s dense, opaque atmosphere, which extends many kilometres above its surface and increases its apparent diameter. titan ' s diameter and mass ( and


km ) and thus the largest moon in the solar system ; this was an overestimation caused by titan ' s dense, opaque atmosphere, which extends many kilometres above its surface and increases its apparent diameter. titan ' s diameter and mass ( and thus its density ) are similar to those of the jovian moons ganymede and callisto. based on its bulk density of 1. 88 g / cm3, titan ' s bulk composition is half water ice and half rocky material. though similar in composition to dione and enceladus, it is denser due to gravitational compression. titan is likely differentiated into several layers with a 3, 400 km rocky center surrounded by several layers composed of different crystal forms of ice. its interior may still be hot and there may be a liquid layer consisting of a " magma " composed of water and ammonia between the ice ih crust and deeper ice layers made of high - pressure forms of ice. the presence of ammonia allows water to remain liquid even at temperatures as low as 176 k ( −97 °c ) ( for eutectic mixture with water ). evidence for such an ocean has recently been uncovered by the cassini probe in the form of natural extremely - low - frequency ( elf ) radio waves in titan ' s atmosphere. titan ' s surface is thought to be a poor reflector of elf waves, so they may instead be reflecting off the liquid – ice boundary of a subsurface ocean. surface features were observed by the cassini spacecraft to systematically shift by up to 30 km between october 2005 and may 2007, which suggests that the crust is decoupled from the interior, and provides additional evidence for an interior liquid layer. | size comparison : titan in infrared ( lower left ) with the moon and earth ( top and right ) | | titan ' s theorized internal structure | | mass comparison : at 96 % of their total mass, titan dominates the saturnian moons | the moons of jupiter and saturn are thought to have formed through co - accretion, a similar process to that believed to have formed the planets in the solar system. as the young gas giants formed, they were surrounded by discs of material that gradually coalesced into moons. however, while jupiter possesses four large satellites in highly - regular, planet - like orbits, titan overwhelmingly dominates saturn ' s system and possesses a high orbital eccentricity not immediately explained by co - accretion alone. a proposed model for the formation of titan is that saturn ' s system began with a group of moons similar to jupiter


orbits, titan overwhelmingly dominates saturn ' s system and possesses a high orbital eccentricity not immediately explained by co - accretion alone. a proposed model for the formation of titan is that saturn ' s system began with a group of moons similar to jupiter ' s galilean satellites, but that they were disrupted by a series of giant impacts, which would go on to form titan. saturn ' s mid - sized moons, such iapetus and rhea, were formed from the debris of these collisions. such a violent beginning would also explain titan ' s orbital eccentricity. titan is the only known moon with more than a trace of atmosphere. its atmosphere is the only nitrogen - rich dense atmosphere in the solar system aside from earth ' s. observations of the atmosphere, made in 2004 by cassini, suggest that titan is a " super rotator ", like venus, with an atmosphere that rotates much faster than its surface. observations from the voyager space probes have shown that the titanian atmosphere is denser than earth ' s, with a surface pressure about 1. 45 times that of earth ' s. titan ' s atmosphere is about 1. 19 times as massive as earth ' s overall, or about 7. 3 times more massive on a per surface area basis. it supports opaque haze layers that block most visible light from the sun and other sources and renders titan ' s surface features obscure. titan ' s lower gravity means that its atmosphere is far more extended than earth ' s. the atmosphere of titan is opaque at many wavelengths and a complete reflectance spectrum of the surface is impossible to acquire from orbit. it was not until the arrival of the cassini – huygens mission in 2004 that the first direct images of titan ' s surface were obtained. the atmospheric composition in the stratosphere is 98. 4 % nitrogen with the remaining 1. 6 % composed mostly of methane ( 1. 4 % ) and hydrogen ( 0. 1 – 0. 2 % ). there are trace amounts of other hydrocarbons, such as ethane, diacetylene, methylacetylene, acetylene and propane, and of other gases, such as cyanoacetylene, hydrogen cyanide, carbon dioxide, carbon monoxide, cyanogen, argon and helium. the hydrocarbons are thought to form in titan ' s upper atmosphere in reactions resulting from the breakup of methane by the sun ' s ultraviolet light, producing a thick orange smog. titan spends 95 % of its time within saturn


sunlight. when the seasons switch, it is expected that ethane will begin to condense over the south pole. the surface of titan has been described as " complex, fluid - processed, [ and ] geologically young ". titan has been around since the solar system ' s formation, but its surface is much younger, between 100 million and 1 billion years old. geological processes may have reshaped titan ' s surface. titan ' s atmosphere is twice as thick as the earth ' s, making it difficult for astronomical instruments to image its surface in the visible light spectrum. the cassini spacecraft is using infrared instruments, radar altimetry and synthetic aperture radar ( sar ) imaging to map portions of titan during its close fly - bys of titan. the first images revealed a diverse geology, with both rough and smooth areas. there are features that seem volcanic in origin, which probably disgorge water mixed with ammonia. there are also streaky features, some of them hundreds of kilometers in length, that appear to be caused by windblown particles. examination has also shown the surface to be relatively smooth ; the few objects that seem to be impact craters appeared to have been filled in, perhaps by raining hydrocarbons or volcanoes. radar altimetry suggests height variation is low, typically no more than 150 meters. occasional elevation changes of 500 meters have been discovered and titan has mountains that sometimes reach several hundred meters to more than 1 kilometer in height. titan ' s surface is marked by broad regions of bright and dark terrain. these include xanadu, a large, reflective equatorial area about the size of australia. it was first identified in infrared images from the hubble space telescope in 1994, and later viewed by the cassini spacecraft. the convoluted region is filled with hills and cut by valleys and chasms. it is criss - crossed in places by dark lineaments — sinuous topographical features resembling ridges or crevices. these may represent tectonic activity, which would indicate that xanadu is geologically young. alternatively, the lineaments may be liquid - formed channels, suggesting old terrain that has been cut through by stream systems. there are dark areas of similar size elsewhere on titan, observed from the ground and by cassini ; it had been speculated that these are methane or ethane seas, but cassini observations seem to indicate otherwise ( see below ). | mosaic of titan from cassini ' s february 2005 flyby. the large dark region is shangri - la. |


had been speculated that these are methane or ethane seas, but cassini observations seem to indicate otherwise ( see below ). | mosaic of titan from cassini ' s february 2005 flyby. the large dark region is shangri - la. | | titan in false color showing surface details and atmosphere with xanadu in the bright region at the center - right. | | titan globe, a mosaic of infrared images with nomenclature | the possibility of hydrocarbon seas on titan was first suggested based on voyager 1 and 2 data that showed titan to have a thick atmosphere of approximately the correct temperature and composition to support them, but direct evidence was not obtained until 1995 when data from hubble and other observations suggested the existence of liquid methane on titan, either in disconnected pockets or on the scale of satellite - wide oceans, similar to water on earth. the cassini mission confirmed the former hypothesis, although not immediately. when the probe arrived in the saturnian system in 2004, it was hoped that hydrocarbon lakes or oceans might be detectable by reflected sunlight from the surface of any liquid bodies, but no specular reflections were initially observed. near titan ' s south pole, an enigmatic dark feature named ontario lacus was identified ( and later confirmed to be a lake ). a possible shoreline was also identified near the pole via radar imagery. following a flyby on july 22, 2006, in which the cassini spacecraft ' s radar imaged the northern latitudes ( that were then in winter ), a number of large, smooth ( and thus dark to radar ) patches were seen dotting the surface near the pole. based on the observations, scientists announced " definitive evidence of lakes filled with methane on saturn ' s moon titan " in january 2007. the cassini – huygens team concluded that the imaged features are almost certainly the long - sought hydrocarbon lakes, the first stable bodies of surface liquid found outside of earth. some appear to have channels associated with liquid and lie in topographical depressions. the liquid erosion features appear to be a very recent occurrence : channels in some regions have created surprisingly little erosion, suggesting erosion on titan is extremely slow, or some other recent phenomena may have wiped out older riverbeds and landforms. overall, the cassini radar observations have shown that lakes cover only a few percent of the surface, making titan much drier than earth. although most of the lakes are concentrated near the poles ( where the relative lack of sunlight prevents evaporation ), a number of long - standing hydrocarbon lakes in


cover only a few percent of the surface, making titan much drier than earth. although most of the lakes are concentrated near the poles ( where the relative lack of sunlight prevents evaporation ), a number of long - standing hydrocarbon lakes in the equatorial desert regions have also been discovered, including one near the huygens landing site in the shangri - la region, which is about half the size of utah ' s great salt lake. the equatorial lakes are probably " oases ", i. e. the likely supplier is underground aquifers. in june 2008, the visual and infrared mapping spectrometer on cassini confirmed the presence of liquid ethane beyond doubt in ontario lacus. on december 21, 2008, cassini passed directly over ontario lacus and observed specular reflection in radar. the strength of the reflection saturated the probe ' s receiver, indicating that the lake level did not vary by more than 3 mm ( implying either that surface winds were minimal, or the lake ' s hydrocarbon fluid is viscous ). specular reflections are indicative of a smooth, mirror - like surface, so the observation corroborated the inference of the presence of a large liquid body drawn from radar imaging. the observation was made soon after the north polar region emerged from 15 years of winter darkness. on july 8, 2009, cassini ' s vims observed a specular reflection indicative of a smooth, mirror - like surface, off what today is called jingpo lacus, a lake in the north polar region shortly after the area emerged from 15 years of winter darkness. radar measurements made in july 2009 and january 2010 indicate that ontario lacus is extremely shallow, with an average depth of 0. 4 – 3. 2 m, and a maximum depth of 2. 9 – 7. 4 m. in contrast, the northern hemisphere ' s ligeia mare has depths exceeding 8 m, the maximum measurable by the radar instrument. during a flyby on 26 september 2012, cassini ' s radar detected in titan ' s northern polar region what is likely a river with a length of more than 400 kilometers. it has been compared with the much larger nile river on earth. this feature ends in ligeia mare. during six flybys of titan from 2006 to 2011, cassini gathered radio - metric tracking and optical navigation data from which investigators could roughly infer titan ' s changing shape. the density of titan is consistent with a body that is about 60 % rock and 40 % water. the team '


to 2011, cassini gathered radio - metric tracking and optical navigation data from which investigators could roughly infer titan ' s changing shape. the density of titan is consistent with a body that is about 60 % rock and 40 % water. the team ' s analyses suggest that titan ' s surface can rise and fall by up to 10 metres during each orbit. that degree of warpage suggests that titan ' s interior is relatively deformable, and that the most likely model of titan is one in which an icy shell dozens of kilometres thick floats atop a global ocean. the team ' s findings, together with the results of previous studies, hint that titan ' s ocean may lie no more than 100 km below its surface. | photo of infrared specular reflection off jingpo lacus, a lake in the north polar region | | perspective radar view of bolsena lacus ( lower right ) and other northern hemisphere hydrocarbon lakes | | contrasting images of the number of lakes in titan ' s northern hemisphere ( left ) and southern hemisphere ( right ) | | two images of titan ' s southern hemisphere acquired one year apart, showing changes in south polar lakes | radar, sar and imaging data from cassini have revealed few impact craters on titan ' s surface. these impacts appear to be relatively young, opposed to titan ' s age. the few impact craters discovered include a 440 km wide two - ring impact basin named menrva seen by cassini ' s iss as a bright - dark concentric pattern. a smaller, 60 km wide, flat - floored crater named sinlap and a 30 km crater with a central peak and dark floor named ksa have also been observed. radar and cassini imaging have also revealed a number of " crateriforms ", circular features on the surface of titan that may be impact related, but lack certain features that would make identification certain. for example, a 90 km wide ring of bright, rough material known as guabonito has been observed by cassini. this feature is thought to be an impact crater filled in by dark, windblown sediment. several other similar features have been observed in the dark shangri - la and aaru regions. radar observed several circular features that may be craters in the bright region xanadu during cassini ' s april 30, 2006 flyby of titan. many of titan ' s craters or probable craters display evidence of extensive erosion, and all show some indication of modification. most large craters have breached or incomplete rims, despite the fact that some craters on titan


april 30, 2006 flyby of titan. many of titan ' s craters or probable craters display evidence of extensive erosion, and all show some indication of modification. most large craters have breached or incomplete rims, despite the fact that some craters on titan have relatively more massive rims than those anywhere else in the solar system. however, there is little evidence of formation of palimpsests through viscoelastic crustal relaxation, unlike on other large icy moons. most craters lack central peaks and have smooth floors, possibly due to impact - generation or later eruption of cryovolcanic lava. while infill from various geological processes is one reason for titan ' s relative deficiency of craters, atmospheric shielding also plays a role ; it is estimated that titan ' s atmosphere reduces the number of craters on its surface by a factor of two. the limited high - resolution radar coverage of titan obtained through 2007 ( 22 % ) suggested the existence of a number of nonuniformities in its crater distribution. xanadu has 2 – 9 times more craters than elsewhere. the leading hemisphere has a 30 % higher density than the trailing hemisphere. there are lower crater densities in areas of equatorial dunes and in the north polar region ( where hydrocarbon lakes and seas are most common ). pre - cassini models of impact trajectories and angles suggest that where the impactor strikes the water ice crust, a small amount of ejecta remains as liquid water within the crater. it may persist as liquid for centuries or longer, sufficient for " the synthesis of simple precursor molecules to the origin of life ". cryovolcanism and mountains scientists have long speculated that conditions on titan resemble those of early earth, though at a much lower temperature. the detection of argon 40 in the atmosphere in 2004 indicated that volcanoes had spawned plumes of " lava " composed of water and ammonia. global maps of the lake distribution on titan ' s surface revealed that there is not enough surface methane to account for its continued presence in its atmosphere, and thus that a significant portion must be added through volcanic processes. still there is a paucity of surface features that can be unambiguously interpreted as cryovolcanoes. one of the first of such features revealed by cassini radar observations in 2004, called ganesa macula, resembles the geographic features called " pancake domes " found on venus, and was thus initially thought to be cryovolcanic in origin, although the american geophysical union refuted this hypothesis in december 2008. the feature


ganesa macula, resembles the geographic features called " pancake domes " found on venus, and was thus initially thought to be cryovolcanic in origin, although the american geophysical union refuted this hypothesis in december 2008. the feature was found to be not a dome at all, but appeared to result from accidental combination of light and dark patches. in 2004 cassini also detected an unusually bright feature ( called tortola facula ), which was interpreted as a cryovolcanic dome. no similar features have been identified as of 2010. in december 2008, astronomers announced the discovery of two transient but unusually long - lived " bright spots " in titan ' s atmosphere, which appear too persistent to be explained by mere weather patterns, suggesting they were the result of extended cryovolcanic episodes. in march, 2009, structures resembling lava flows were announced in a region of titan called hotei arcus, which appears to fluctuate in brightness over several months. though many phenomena were suggested to explain this fluctuation, the lava flows were found to rise 200 meters above titan ' s surface, consistent with it having been erupted from beneath the surface. a mountain range measuring 150 km long, 30 km wide and 1. 5 km high was also discovered by cassini in 2006. this range lies in the southern hemisphere and is thought to be composed of icy material and covered in methane snow. the movement of tectonic plates, perhaps influenced by a nearby impact basin, could have opened a gap through which the mountain ' s material upwelled. prior to cassini, scientists assumed that most of the topography on titan would be impact structures, yet these findings reveal that similar to earth, the mountains were formed through geological processes. in december 2010, the cassini mission team announced the most compelling possible cryovolcano yet found. named sotra patera, it is one in a chain of at least three mountains, each between 1000 and 1500 m in height, several of which are topped by large craters. the ground around their bases appears to be overlaid by frozen lava flows. if volcanism on titan really exists, the hypothesis is that it is driven by energy released from the decay of radioactive elements within the mantle, as it is on the earth. magma on earth is made of liquid rock, which is less dense than the solid rocky crust through which it erupts. because ice is less dense than water, titan ' s watery magma would be denser than its solid icy crust. this means


magma on earth is made of liquid rock, which is less dense than the solid rocky crust through which it erupts. because ice is less dense than water, titan ' s watery magma would be denser than its solid icy crust. this means that cryovolcanism on titan would require a large amount of additional energy to operate, possibly via tidal flexing from nearby saturn. alternatively, the pressure necessary to drive the cryovolcanoes may be caused by ice ih " underplating " titan ' s outer shell. the low - pressure ice, overlaying a liquid layer of ammonium sulfate, ascends buoyantly, and the unstable system can produce dramatic plume events. titan is resurfaced through the process by grain - sized ice and ammonium sulfate ash, which helps produce a wind - shaped landscape and sand dune features. in 2008 jeffrey moore ( planetary geologist of ames research center ) proposed an alternate view of titan ' s geology. noting that no volcanic features had been unambiguously identified on titan so far, he asserted that titan is a geologically dead world, whose surface is shaped only by impact cratering, fluvial and eolian erosion, mass wasting and other exogenic processes. according to this hypothesis, methane is not emitted by volcanoes but slowly diffuses out of titan ' s cold and stiff interior. ganesa macula may be an eroded impact crater with a dark dune in the center. the mountainous ridges observed in some regions can be explained as heavily degraded scarps of large multi - ring impact structures or as a result of the global contraction due to the slow cooling of the interior. even in this case titan may still have an internal ocean made of the eutectic water – ammonia mixture with the temperature of 176 k ( −97 °c ), which is low enough to be explained by the decay of radioactive elements in the core. the bright xanadu terrain may be a degraded heavily cratered terrain similar to that observed on the surface of callisto. indeed, were it not for its lack of an atmosphere, callisto could serve as a model for titan ' s geology in this scenario. jeffrey moore even called titan callisto with weather. in the first images of titan ' s surface taken by earth - based telescopes in the early 2000s, large regions of dark terrain were revealed straddling titan ' s equator. prior to the arrival of cassini, these regions were thought to be seas of organic matter like tar or liquid hydrocarbons. radar images captured