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A run-flat tire is a pneumatic vehicle tire that is designed to resist the effects of deflation when punctured, and to enable the vehicle to continue to be driven at reduced speeds (up to 55 mph (90 km/h)), and for limited distances of up to 100 mi (160 km), or even 200 mi (320 km) depending on the type of tire. The origins of the commercial self-supporting run-flat tire started in 1935 with a tire that had a fabric inner tire. The tire was advertised as a protection against blow outs, a common and dangerous occurrence in the 1930s. In 1934, Michelin introduced a tire that was based on technology developed for local commuter trains and trolleys. It had a safety rim inside the tire which if punctured would run on a special foam lining. The tire was sold for military use and for specialized vehicles like bank armoured cars. It was advertised as "semi-bullet proof". While the tire performed as advertised it was far too expensive to be a feasible option for private automobile users. In 1958, Chrysler teamed with Goodyear Tire and Rubber Company to offer Captive Air run-flat tires using an interlining to carry the weight. In 1972 Dunlop launched the Denovo "fail-safe" wheel and tyre system that became optional equipment on the Rover P6 3500 in 1973, and by 1983 evolved into the TD/Denloc which became standard equipment across the whole Austin Metro range. Most recently, Bridgestone run-flat tires are supplied on some new model BMW cars. The automaker promoted these as a safety feature and as an alternative to carrying a spare tire. Self-supporting run-flat tires are now common on light trucks and passenger cars and typically provide for the vehicle to drive for 50 miles (80 km) at around 50 miles per hour (80 km/h). However, if the tires are subject to this kind of misuse, they may become irreparably damaged in the process. In addition, if the tire is punctured in the sidewall or at the edge of the tread, repair may be impossible or unsafe. These tires carry a 20 to 40 percent weight penalty over similar standard tires. Some run-flat tires have a 20% higher rolling resistance, in part due to their added structural material and mass. On the other hand, internal bracing in some run-flat tires reduces deformation, with the opposite effects of reducing rolling resistance and improving fuel efficiency. Run-flat tires accounted for less than 1% of replacement tire sales in the U.S. in 2005. In 2006, it was expected that such tires would gain popularity with armored vehicle manufacturers, but growth figures were slow with one major model, the Michelin PAX System, no longer being developed by the manufacturer (though replacements will be produced for the foreseeable future). A Michelin study released in 2008 found that only 3 percent of drivers worldwide want run-flat tires. [READ THE REST OF THIS ARTICLE]





The Borei class (or Borei; named after Boreas, the North wind) is a type of nuclear-powered ballistic missile submarine produced and operated by Russia. It is intended to replace the Delta III and Typhoon class in the Russian Navy. The Borei is claimed to represent the state of the art in submarine design, incorporating characteristics that make it superior to any submarine currently in service, such as the ability to cruise silently and be less detectable to sonar. Advances include a compact and integrated hydrodynamically efficient hull for reduced broadband noise and the first ever use of pump-jet propulsion on a Russian nuclear submarine. Costing some $890 million USD, Borei is approximately 170 metres (560 ft) long, 13 metres (43 ft) in diameter, and has a maximum submerged speed of at least 46 kilometres per hour (25 kn; 29 mph). The launch of the first submarine of the class, the Yury Dolgorukiy, was scheduled for 2002 but was delayed because of budget constraints. The vessel was eventually rolled out of its construction hall on 15 April 2007 in a ceremony attended by many senior military and industrial personnel. The Yuriy Dolgorukiy was the first strategic missile submarine to be launched in the seventeen years since the end of the Soviet era; in fact, it was the first Russian (rather than Soviet) vessel. Currently, there are two more Borei class submarines under construction, named Alexander Nevsky and Vladimir Monomakh. However, the SS-N-28 missile that the Borei class was supposed to carry was abandoned after several failed tests, and the submarine was redesigned for the Bulava missile. Based on the Russian Topol-M (SS-27) ICBM the Bulava missile is smaller than the original SS-N-28, and in the 2007 START treaty data exchange it was reported that all Borei-class submarines would carry 16 missiles instead of 12, as originally intended. [READ THE REST OF THIS ARTICLE]



Six Degrees of Kevin Bacon is a trivia game based on the concept of the small world phenomenon and rests on the assumption that any individual can be linked through his or her film roles to actor Kevin Bacon within six steps. The name of the game is a paraphrase of the "six degrees of separation" concept. In 2007, Bacon started a charitable organization named SixDegrees.org. The game requires a group of players to try to connect any individual to Kevin Bacon as quickly as possible and in as few links as possible. The fantasy author-editor Richard Gilliam devised his Movie Links online game in 1990, and it was played extensively on GEnie for years before the quite similar Six Degrees of Kevin Bacon game was promoted in 1994. Gilliam's game was much more difficult in that a player was required to find the shortest number of movies linking actors as diverse as, say, Gloria Swanson and Chris Farley, rather than continual links to the same specific actor. The Bacon number of an actor or actress is the number of degrees of separation he or she has from Bacon, as defined by the game. This is an application of the Erdos number concept to the movie industry. The higher the Bacon number, the farther away from Kevin Bacon the actor is. The computation of a Bacon number for actor X is a "shortest path" algorithm: Kevin Bacon himself has a Bacon number of 0, The Bacon number of actors who have worked directly with Kevin Bacon is 1, If the lowest Bacon number of any actor with whom X has appeared in a movie is N, X's Bacon number is N + 1. Here is an example, using Elvis Presley: Edward Asner was in JFK (1991) with Kevin Bacon, Elvis Presley was in Change of Habit (1969) with Edward Asner, Therefore Asner has a Bacon number of 1, and Presley (who never appeared in a film with Bacon himself) has a Bacon number of 2. As of December 2007, the highest finite Bacon number reported by the Oracle of Bacon is 8. [READ THE REST OF THIS ARTICLE]





A brain tumor (or brain tumour) is an intracranial solid neoplasm, a tumor (defined as an abnormal growth of cells) within the brain or the central spinal canal. Brain tumors include all tumors inside the cranium or in the central spinal canal. They are created by an abnormal and uncontrolled cell division, normally either in the brain itself (neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells, myelin-producing Schwann cells), lymphatic tissue, blood vessels), in the cranial nerves, in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors). Any brain tumor is inherently serious and life-threatening because of its invasive and infiltrative character in the limited space of the intracranial cavity. However, brain tumors (even malignant ones) are not invariably fatal. Brain tumors or intracranial neoplasms can be cancerous (malignant) or non-cancerous (benign); however, the definitions of malignant or benign neoplasms differs from those commonly used in other types of cancerous or non-cancerous neoplasms in the body. Its threat level depends on the combination of factors like the type of tumor, its location, its size and its state of development. Because the brain is well protected by the skull, the early detection of a brain tumor only occurs when diagnostic tools are directed at the intracranial cavity. Usually detection occurs in advanced stages when the presence of the tumor has caused unexplained symptoms. Primary (true) brain tumors are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain. Secondary tumors of the brain are metastatic tumors that invaded the intracranial sphere from cancers originating in other organs. This means that a cancerous neoplasm has developed in another organ elsewhere in the body and that cancer cells have leaked from that primary tumor and then entered the lymphatic system and blood vessels. They then circulate through the bloodstream, and are deposited in the brain. There, these cells continue growing and dividing, becoming another invasive neoplasm of the primary cancer's tissue. Secondary tumors of the brain are very common in the terminal phases of patients with an incurable metastasized cancer; the most common types of cancers that bring about secondary tumors of the brain are lung cancer, breast cancer, malignant melanoma, kidney cancer and colon cancer (in decreasing order of frequency). Secondary brain tumors are the most common cause of tumors in the intracranial cavity. [READ THE REST OF THIS ARTICLE]





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