Aberrations

A lens is a device for either concentrating or diverging light, usually produced from a piece of shaped glass. Lenses do not form perfect images, and there is always some degree of distortion or aberration introduced by the lens which causes the image to be an defective replica of the object. Careful design of the lens system for a exacting application ensures that the aberration is minimized. There are several different types of aberration which can influence image quality.

Automobile

An automobile (also motor car or simply car) is a wheeled traveler vehicle that carries its own motor. Most definitions of the term specify that automobiles are designed to run mostly on roads, to have seating for one to eight people, to typically have four wheels, and to be constructed principally for the transport of people rather than goods.However, the term is far from precise.

The economics of personal automobile ownership go away from the initial cost of the vehicle and includes repairs, maintenance, fuel, depreciation, the cost of borrowing, parking fees, tire replacement, taxes and insurance.The capability for humans to travel rapidly from place to place has far reaching implications for the nature of our society. People can now live faraway from their workplaces, the design of our cities is determined as much by the need to get vehicles into and out of the city as the nature of the buildings and public spaces within the city.

Apple Computer

Apple Computer, Inc. NASDAQ: AAPL is a Silicon Valley company based in Cupertino, California, whose nucleus business is computer technologies. Apple helped originate the personal computer revolution in the 1970s with the Apple II microcomputer and has since further shaped it with the Macintosh. Apple is known for its original, well-designed hardware, such as the iPod and iMac, as well as software offerings exemplified through iTunes as part of the iLife suite and Mac OS X, its flagship operating system.

Multithreading in Java

Java provides built-in support for multithreaded programming. A multithreaded program will have 2 or more parts that can run concurrently. Each part of such a program in java is called a thread, and each thread defines a separate path of execution. It is a specialized form of multitasking. There are two distinct types of multitasking namely Process-based and Thread-based.

A short note on Usable groundwater

A Usable groundwater is enclosed in the aquifers, which are subterranean areas (or the layers) of permeable material (like sand and gravel) that channel the groundwater's flow. The Aquifers can be either confined or unconfined. If a confined aquifer goes after a downward grade from a recharge zone, the groundwater can turn out to be pressurized as it flows. This can form artesian wells that flow freely not including the need of a pump. The top of the upper unconfined aquifer is known as the water table or phreatic surface, where water pressure is equivalent to the atmospheric pressure.