African Commonwealth Nations

African Commonwealth Nations The following alphabetical list gives the date at which each African Country joined the Commonwealth of Nations as an independent state. The majority of African countries joined as Commonwealth Realms, later converting to Commonwealth Republics. Two countries, Lesotho and Swaziland, joined as Kingdoms. British Somaliland (which joined with Italian Somaliland five days after gaining independence in 1960 to form Somalia), and Anglo-British Sudan (which became a republic in 1956) did not become members of the Commonwealth of Nations. Egypt, which had been part of the Empire until 1922, has never shown an interest in becoming a member. African Commonwealth Nations Botswana, 30 September 1966 as a RepublicCameroon, 11 November 1995 as a RepublicThe Gambia, 18 February 1965 as a Realm- became a Republic on 24 April 1970Ghana, 6 March 1957 as a Realm- became a Republic 1 July 1960Kenya, 12 December 1963 as a Realm- became a Republic on 12 December 1964Lesotho, 4 October 1966 as a KingdomMalawi, 6 July 1964 as a Realm- became a Republic on 6 July 1966Mauritius, 12 March 1968 as a realm- became a Republic on 12 March 1992Mozambique, 12 December 1995 as a RepublicNamibia, 21 March 1990 as a republicNigeria, 1 October 1960 as a Realm- became a Republic on 1 October 1963 – suspended between 11 November 1995 and 29 May 1999Rwanda, 28 November 2009 as a RepublicSeychelles, 29 June 1976 as a RepublicSierra Leone, 27 April 1961 as a Realm- became a Republic 19 April 1971South Africa, 3 December 1931 as a Realm- withdrew on becoming a Republic on 31 May 1961, rejoined 1 June 1994Swaziland, 6 September 1968 as a KingdomTanganyika, 9 December 1961 as a Realm- became Republic of Tanganyika on 9 December 1962, United Republic of Tanganyika and Zanzibar on 26 April 1964, and United Republic of Tanzania on 29 October 1964. Uganda, 9 October 1962 as a Realm- became a Republic on 9 October 1963Zambia, 24 October 1964 as a RepublicZimbabwe, 18 April 1980 as a Republic- suspended on 19 March 2002, departed on 8 December 2003

Nitrogen in Tires

Nitrogen in Tires Question: What makes nitrogen in tires better than air? I see a lot of tires with the green cap indicating they are filled with nitrogen. Is there any advantage to putting nitrogen in my automobile tires instead of compressed air? How does it work? Answer: There are multiple reasons why nitrogen is preferable to air in automobile tires: better pressure retention leading to increased fuel economy and improved tire lifespancooler running temperatures accompanied by less pressure fluctuation with temperature changeless tendency toward wheel rot To understand why, its helpful to review the composition of air. Air is mostly nitrogen (78%), with 21% oxygen, and smaller amounts of carbon dioxide, water vapor, and other gases. The oxygen and water vapor are the molecules that matter. Although you might think oxygen would be a larger molecule than nitrogen because it has a higher mass on the periodic table, elements further along an element period actually have a small atomic radius because of the nature of the electron shell. An oxygen molecule, O2, is smaller than a nitrogen molecule, N2, making it easier for oxygen to migrate through the wall of tires. Tires filled with air deflate more quickly than those filled with pure nitrogen. Is it enough to matter? A 2007 Consumer Reports study compared air-inflated tires and nitrogen-inflated tires to see which lost pressure more quickly and whether the difference was significant. The study compared 31 different automobile models with tires inflated to 30 psi. They followed the tire pressure for a year and found air-filled tires lost an average of 3.5 psi, while nitrogen-filled tires lost an average of 2.2 psi. In other words, air-filled tires leak 1.59 times more quickly than nitrogen-filled tires. The leakage rate varied widely between different brands of tires, so if a manufacturer recommends filling a tire with nitrogen, its best to heed the advice. For example, the BF Goodrich tire in the test lost 7 psi. Tire age also mattered. Presumably, older tires accumulate tiny fractures which make them more leaky with time and wear. Water is another molecule of interest. If you only ever fill up your tires with dry air, the effects of water arent a problem, but not all compressors remove water vapor. Water in tires should not lead to tire rot in modern tires because they are coated with aluminum so they will form aluminum oxide when exposed to water. The oxide layer protects the aluminum from further attack in much the same way chrome protects steel. However, if you are using tires that do not have the coating, water can attack the tire polymer and degrade it. The more common problem (which I have noted in my Corvette, when I have used air rather than nitrogen) is that water vapor leads to pressure fluctuations with temperature. If there is water in your compressed air, it enters the tires. As the tires heat up, the water vaporizes and expands, increasing tire pressure much more significantly than what you see from the expansion of nitrogen and oxygen. As the tire cools, pressure drops appreciably. The changes reduce tire life expectancy and affect fuel economy. Again, the magnitude of the effect likely is influenced by brand of tire, age of tire, and how much water you have in your air. The Bottom Line The important thing is to make sure your tires are kept inflated at the proper pressure. This is much more important than whether the tires are inflated with nitrogen or with air. However, if your tires are expensive or you drive under extreme conditions (i.e., at high speeds or with extreme temperature changes over the course of a trip), its worth it to use nitrogen. If you have low pressure but normally fill with nitrogen, its better to add compressed air than wait until you can get nitrogen, but you may see a difference in the behavior of your tire pressure. If there is water in with the air, any problems will likely be lasting, since theres nowhere for the water to go. Air is fine for most tires and preferable for a vehicle youll take to remote locations, since compressed air is much more readily available than nitrogen.