An extract on #piloteyes
Olga was the first ruler of Rus' to convert to Christianity, in either 945 or 957. The ceremonies of her formal reception in Constantinople were minutely described by Emperor Constantine VII in his book De Ceremoniis. Following her baptism, Olga took the Christian name Yelena, after the reigning Empress Helena Lekapena. The Slavonic chronicles add apocryphal details to the account of her baptism, such as the story of how she charmed and "outwitted" Constantine and spurned his proposals of marriage. In actuality, at the time of her baptism, Olga was an old woman, while Constantine already had a wife.
Olga was one of the first people of Rus' to be canonized, proclaimed a saint for her efforts to spread Christianity throughout the country. Because of her proselytizing influence, the Eastern Orthodox Church, the Ruthenian Greek Catholic Church, and the Ukrainian Greek Catholic Church call Saint Olga by the honorific Isapstolos, "Equal to the Apostles". However, she failed to convert Svyatoslav, and it was left to her grandson and pupil, Vladimir I, to make Christianity the lasting state religion. During her son's prolonged military campaigns, she remained in charge of Kiev, residing in the castle of Vyshgorod together with her grandsons. She died soon after the Pechenegs' siege of the city, in 969.
TORNADO an object database for CAD/CAM
Gemstone started (as Servio Logic) to build a set theoretic model data base machine.
1985 Term Object Database first introduced
Servio Logic (Gemstone Systems) Ships Gemstone 1.0
Versant Corporation started (as Object Sciences Corp)
Objectivity, Inc. founded
Servio Logic changes name to Gemstone Systems
VBase (O2- ONTOS INFORMIX)
Versant Object Database
lambda-DB: An ODMG-Based Object-Oriented DBMS by Leonidas Fegaras, Chandrasekhar Srinivasan, Arvind Rajendran, David Maier
db4o project started by Carl Rosenberger
2001 IBM acquires Informix
2003 odbpp public release
2004 db4o's commercial launch as db4objects, Inc.
2008 db4o acquired by Versant Corporation
2010 VMware acquires GemStone
2012 Wakanda first production versions with open source and commercial licenses
2013 GemTalk Systems acquires GemStone products from VMware
The photochemical mechanisms that give rise to the ozone layer were discovered by the British physicist Sydney Chapman in 1930. Ozone in the Earth's stratosphere is created by ultraviolet light striking ordinary oxygen molecules containing two oxygen atoms (O2), splitting them into individual oxygen atoms (atomic oxygen); the atomic oxygen then combines with unbroken O2 to create ozone, O3. The ozone molecule is unstable (although, in the stratosphere, long-lived) and when ultraviolet light hits ozone it splits into a molecule of O2 and an individual atom of oxygen, a continuing process called the ozone-oxygen cycle. Chemically, this can be described as:
O2 + uv 2O
O + O2 O3
About 90 percent of the ozone in the atmosphere is contained in the stratosphere. Ozone concentrations are greatest between about 20 and 40 kilometres (66,000 and 131,000 ft), where they range from about 2 to 8 parts per million. If all of the ozone were compressed to the pressure of the air at sea level, it would be only 3 millimetres (18 inch) thick.