LISA. physics.chem.bio.

Sunday, April 5, 2009

Tallest buildings in the world.

Rank	Building	City	Country	Height		Floors	Built
1	Burj Dubai	Dubai	United Arab Emirates	818 m	2,684 ft	162	2009
2	Taipei 101	Taipei	Taiwan	509 m	1,671 ft	101	2004
3	Shanghai World Financial Center	Shanghai	China	492 m	1,614 ft	101	2008
4=	Petronas Tower 1	Kuala Lumpur	Malaysia	452 m	1,483 ft	88	1998
4=	Petronas Tower 2	Kuala Lumpur	Malaysia	452 m	1,483 ft	88	1998
6	Nanjing Greenland Financial Center	Nanjing	China	450 m	1,476 ft	89	2009^[C]
7	Sears Tower	Chicago	United States	442 m	1,451 ft	108	1973
8	Guangzhou International Finance Center	Guangzhou	China	438 m	1,435 m	103	2009
9	Jin Mao Tower	Shanghai	China	421 m	1,380 ft	88	1998
10=	Two International Finance Centre	Hong Kong	Hong Kong, China	415 m	1,362 ft	88	2003
10=	Trump International Hotel and Tower	Chicago	United States	415 m	1,362 ft	92	2009

source: Wikipedia

your name @ 3:49 PM | your comment link

Mount Redoubt erupted 6 times.
On the 22 - 23 March 2009, Mt Redoubt erupted 6 times, spewing ash 60,000 feet up in the air. Mt. Redoubt had erupted several times before, most notably for five months in late 1989 through 1990, when its ash stopped the engines of a KLM jet in mid-flight. The plane dropped two miles before its crew could reactivate the engines. The jagged particles that constitute ash from volcanoes such as Mt. Redoubt do more than shred machinery. They can tear into eyes and skin and cause breathing problems.

source: latimes.com

your name @ 3:23 PM | your comment link

Why did World Trade Center fall?
The impact of the plane crash destroyed some of the load-bearing columns and inflicted other structural damage in both towers. The resulting explosions ignited 10,000 US gallons (38,000 l) of jet fuel. The light construction and hollow nature of the buildings allowed the fuel to penetrate far inside the towers igniting large fires simultaneously. The fires were hot enough to weaken the steel columns and cause floors to sag, pulling perimeter columns inward and reducing their ability to support the mass of the building above.

source: Wikipedia

your name @ 2:48 PM | your comment link

Thursday, April 2, 2009

Chemistry.
Chemistry (from Egyptian kēme (chem), meaning "earth") is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions. It is a physical science for studies of various atoms, molecules, crystals and other aggregates of matter whether in isolation or combination, which incorporates the concepts of energy and entropy in relation to the spontaneity of chemical processes. Modern chemistry evolved out of alchemy following the chemical revolution (1773).

Disciplines within chemistry are traditionally grouped by the type of matter being studied or the kind of study. These include inorganic chemistry, the study of inorganic matter; organic chemistry, the study of matter; biochemistry, the study of substances found in biological organisms; physical chemistry, the energy related studies of chemical systems at macro, molecular and submolecular scales; analytical chemistry, the analysis of material samples to gain an understanding of their chemical composition and structure. Many more specialized disciplines have emerged in recent years, e.g. neurochemistry the chemical study of the nervous system.

Chemistry is the scientific study of interaction of chemical substances that are constituted of atoms or the subatomic particles: protons, electrons and neutrons. Atoms combine to produce molecules or crystals. Chemistry is often called "the central science" because it connects the other natural sciences such as astronomy, physics, material science, biology, and geology.

source: Wikipedia

useful links:

www.chem4kids.com

yahoo!directory

your name @ 3:58 PM | your comment link