Sunday, February 25, 2007

Cast iron

Cast iron generally refers to grey cast iron, but can mean any of a group of iron-based alloys containing more than 2% carbon. It is made by remelting pig iron, often along with substantial quantities of scrap iron and scrap steel, and taking a variety of steps to remove undesirable contaminants such as phosphorus and sulfur. Carbon and silicon content are reduced to the desired levels, which may be anywhere from 2% to 3.5% for carbon and 1% to 3% for silicon depending on the application. Other elements are then added to the melt before the final form is shaped by casting.
Iron is most commonly melted in a small blast furnace known as a cupola. After melting is complete, the molten iron is removed or ladled from the forehearth of the blast furnace. This process is thought to have been devised by the late 18th century ironmaster John Wilkinson, whose innovative ideas revolutionized the field of metallurgy. Previously, iron was melted in an air furnace, which is a type of reverberatory furnace.

Tuesday, February 20, 2007

Classification of Tamil

Tamil is associate of the Tamil language family, which includes the Irula, Kaikadi, Betta Kurumba, Sholaga, and Yerukula languages. This group is a subgroup of the Tamil-Malayalam languages, which falls under a subgroup of the Tamil-Kodagu languages, which in turn is a subgroup of the Tamil-Kannada languages. The Tamil-Kannada languages belong to the southern branch of the Dravidian language family. Tamil is most directly related to Malayalam, spoken in the Indian state of Kerala which borders Tamil Nadu. Linguists estimate Malayalam divided from Tamil between the 8th and 10th centuries.

Wednesday, February 14, 2007

Ice cream

Before the growth of modern refrigeration, ice cream was a luxury item kept for special occasions. Making ice cream was quite difficult. Ice was cut commercially from lakes and ponds during the winter and stored in large heaps in holes in the ground or in wood-frame ice houses, insulated by straw. Ice cream was made by hand in a huge bowl enclosed by packed ice and salt. The temperature of the ingredients was reduced by the mix of compressed ice and salt. The salt water was chilled by the ice, and the action of the salt on the ice causes it to (partially) melt, absorbing latent heat bringing the combination below the freezing point of pure water. The wrapped up container can also make better thermal contact with the salty water and ice mixture than it could with ice alone.The hand-cranked churn, which still used ice and salt for cooling, was made-up by an American named Nancy Johnson in 1846, making invention possible on site and avoiding the problem of nonstop chilling between production and consumer. Ice cream became a trendy item for the first time. The world's first business ice cream factory was opened in Baltimore, Maryland in 1851, by Jacob Fussell, a dairy farmer. An unstable demand for his milk led him to mass create ice cream. This allowed the previously expensive invention to be offered in the city at reduced prices.Fussell opened ice cream parlors as far west as Texas. Many were still around well into the twentieth century. Fussell later sold his business to Borden.
The improvement of industrial refrigeration by German engineer Carl von Linde during the 1870s eliminated the need to cut and store natural ice and when the continuous-process freezer was perfected in 1926, allowed commercial mass invention of ice cream and the birth of the modern ice cream industry.The most common method for producing ice cream at home is to use an ice cream maker, in modern times normally an electrical device that churns the ice cream mixture while cooled inside a house freezer, or using ice and salt. A newer method of making home-made ice cream is to add liquid nitrogen to the mixture while moving it using a spoon or spatula.

Sunday, February 11, 2007

Diamond

Diamonds do not show all of their attractiveness as rough stones; instead, they must be cut and polished to exhibit the characteristic fire and intensity that diamond gemstones are known for. Diamonds are cut into a variety of shapes that are commonly designed to accentuate these features.Diamonds which are not cut to the specifications of round brilliant shape (or subsequent variations) are known as "fancy cuts." Popular fancy cuts include the baguette (from the French, meaning rod or loaf of bread), marquise, princess (square outline), heart, briolette (a form of the rose cut), and pear cuts. Newer cuts that have been introduced into the jewelry industry are the "cushion" "radiant"(similar to princess cuts, but with rounded edges instead of square edges) and "Asscher" cuts. Many fancy colored diamonds are now being cut according to these new styles. Generally speaking, these "fancy cuts" are not held to the same strict standards as Tolkowsky-derived round brilliants and there are less specific mathematical guidelines of angles which determine a well-cut stone. Cuts are influenced heavily by fashion: the baguette cut—which accentuates a diamond's luster and downplays its fire—was all the rage during the Art Deco period, whereas the princess cut—which accentuates a diamond's fire rather than its luster—is currently gaining popularity. The princess cut is also popular amongst diamond cutters: of all the cuts, it wastes the least of the original crystal. The past decades have seen the development of new diamond cuts, often based on a modification of an existing cut. Some of these include extra facets. These newly developed cuts are viewed by many as more of an attempt at brand differentiation by diamond sellers, than actual improvements to the state of the art

Monday, February 05, 2007

Software

Software basically is the distinct image or representation of physical or material position that constitute configuration to or functional identity of a machine, usually a computer. As a substance of memory, software in principle can be changed without the alteration to the static paradigm of the hardware thus without the remanufacturing thereof. generally software is of an algorithmic form which translates into being to a progression of machine instructions. Some software, however, is of a relational form which translate into being the map of a recognition network.

Software is a program that enables a computer to achieve a specific task, as contrasting to the physical components of the system (hardware). This include application software such as a word processor, which enables a user to achieve a task, and system software such as an operating system, which enables other software to run suitably, by interfacing with hardware and with other software.

The term "software" was first used in this intellect by John W. Tukey in 1957. In computer science and software engineering, computer software is all computer program. The perception of reading different sequences of instructions into the memory of a apparatus to control computations was invented by Charles Babbage as part of his difference engine. The theory that is the source for most modern software was first projected by Alan Turing in his 1935 essay Computable numbers with an application to the Entscheidungs problem.

Types
Practical computer systems partition software into three major classes: system software, programming software and application software, although the division is subjective, and often blurred.

* System software is one of the major class helps run the computer hardware and computer system. It includes working systems, device drivers, analytical tools, servers, windowing systems, utilities and more. The intention of systems software is to protect the applications programmer as much as possible from the details of theexacting computer complex being use, especially memory and other hardware features, and such accessory procedure as communications, printers, readers, displays, keyboards, etc.

* Programming software usually provide tools to support a programmer in writing computer programs and software with different programming languages in a more suitable way.The tools comprise text editors, compilers, interpreters, linkers, debuggers, and so on, An incorporated development environment (IDE) merge those tools into a software bundle, and a programmer may not need to type various command for compiling, interpreter, debugging, tracing, and etc., because the IDE typically has an sophisticated graphical user interface, or GUI.

* Application software allows humans to complete one or more explicit (non-computer related) tasks. typical applications include manufacturingautomation, business software, educational software, medical software, databases and computer games. Businesses are possibly the biggest users of application software, but approximately every field of human action now uses some form of application software. It is used tocomputerizeall sorts of functions.