Monday, January 28, 2008

Minicomputer

Minicomputer is a mostly outmoded term for a class of multi-user computers which generate the middle range of the computing spectrum, in between the largest multi-user systems (traditionally, mainframe computers) and the smallest single-user systems (microcomputers or personal computers). Formerly this class created a distinct group with its own hardware and operating systems notably having smaller address space (notice the cited numbers of bits in a data word, ranging from 8 to 24 bits commonly around 16-bits). While the distinction between mainframe computers and smaller computers residue fairly clear, contemporary middle-range computers are not well differentiated from personal computers, being typically just a more powerful but still compatible version of a personal computer. More modern conditions for such machines consist of midrange systems (common in IBM parlance), workstations (common in Sun Microsystems and general UNIX/Linux parlance), and servers.

Sunday, January 20, 2008

Microcomputer

A microcomputer is mostly often taken to mean a computer with a microprocessor (µP) as its CPU. Another common characteristic of these computers is that they take up physically small amounts of space. Desktop computers, video game consoles, laptop computers, tablet PCs, and a lot of handheld strategy may all be considered examples of microcomputers. Most microcomputers serve only a particular user at a time, but some, in the form of PCs and workstations running e.g. a UNIX(-like) operating system, may cater to a number of users concurrently. The µP does the greater part of the job of calculating on and manipulating data that all computers do.

Monday, January 07, 2008

Mainframes

Mainframes (often colloquially referred to as big iron) are enormous and expensive computers used mostly by government institutions and large companies for mission critical applications, usually bulk data processing such as censuses, industry/consumer statistics, ERP, and financial transaction processing.

The term originated during the early 1970s with the introduction of lesser, fewer complex computers such as the DEC PDP-8 and PDP-11 series, which became known as minicomputers or in a minute minis. The industry/users then coined the term "mainframe" to describe bigger, earlier types (previously known simply as "computers").

Tuesday, January 01, 2008

The first bullets

Advances in one either resulted beginning or precipitated advances in the other. Originally, bullets were surrounding metallic or stone balls placed in front of an explosive charge of gun powder at the end of a closed tube. As firearms became more scientifically advanced, from 1500 to 1800, bullets changed very little. They remained uncomplicated round lead balls, called rounds, differing only in their diameter.

The development of the hand culverin and matchlock arquebus brought regarding the use of cast lead balls as projectiles. "Bullet" is consequential from the French word "boulette" which roughly means "little ball". The original musket bullet was a spherical lead ball two sizes slighter than the bore, wrapped in a loosely-fitted paper patch which served to hold the bullet in the barrel firmly upon the powder. (Bullets that were not firmly upon the concentrate upon firing risked causing the barrel to explode, with the condition known as a "short start".) The loading of muskets was, therefore, easy with the old smooth-bore Brown Bess and comparable military muskets. The original muzzle-loading rifle, on the other hand, with a more intimately fitting ball to take the rifling grooves, was loaded with difficulty, particularly when the bore of the barrel was dirty from previous firings ("fouled"). For this reason, early rifles were not generally used for military purposes. Early rifle bullets necessary cloth patches to grip the rifling grooves, and to hold the bullet securely against the powder.

The first half of the nineteenth century saw a different change in the shape and function of the bullet. In 1826, Delirque, a French infantry officer, imaginary a breech with abrupt shoulders on which a spherical bullet was rammed down until it caught the rifling grooves.

Tuesday, December 25, 2007

Bullet

A bullet is a rock-hard projectile propelled by a firearm or air gun and is normally made from metal (usually lead). A bullet (in contrast to a shell) does not contain explosives, and damages the intended target solely by imparting kinetic energy upon impact. Modern bullets for firearms are generally part of a cartridge, also known as a round. In contrast, bullets for air guns are not part of a cartridge. The word "bullet" is sometimes used to refer to the grouping of bullet, case, gunpowder and primer more properly known as a cartridge or round.; the Oxford English Dictionary definition of a bullet is "a projectile of lead ... for firing from a rifle, revolver etc."

Monday, December 17, 2007

JAR Files

A JAR file has a manifest file situated in the path META-INF/MANIFEST.MF. The entries in the manifest file conclude how the JAR file will be used. JAR files which are intended to be executed as separate programs will have one of their classes specified as the "main" class. The obvious file would have an entry such as

Main-Class: myPrograms.MyClass

Such JAR files are characteristically started with a command similar to

java -jar foo.jar

These files can also include a Classpath entry, which identifies other JAR files to be overloaded with the JAR. This entry consists of a list of absolute or relation paths to other JAR files. Although intended to simplify JAR use, in practice, it turns out to be infamously brittle as it depends on all the relevant JARs being in the exact locations specified when the entry-point JAR was built. To change versions or locations of libraries, a new manifest is required.

Wednesday, December 12, 2007

JAR

In computing, a JAR file (or Java ARchive) file used to deal out a set of Java classes. It is used to store compiled Java classes and connected metadata that can constitute a program.

* WAR (file format) (Web Application aRchive) files are also Java archives which store XML files, java classes, Java Server Pages and extra objects for Web Applications.

* EAR (file format) (Enterprise ARchive) files are also Java archives which store XML files, java classes and additional objects for Enterprise Applications.

* RAR (file format) (Resource Adapter aRchive) files are also Java archives which store XML files, java classes and added objects for J2EE Connector Architecture (JCA) applications.

JAR files can be created and extracted by the "jar" command that comes with the JDK. It can be done using zip tools, but as WinZip has a custom of renaming all-uppercase directories and files in lower case, this can raise support calls with whoever shaped the JAR or the tool authors themselves. WinRAR, on the additional hand, retains the original case of filenames.

Tuesday, December 04, 2007

Grape

A grape is the non-climacteric fruit that grows on the permanent and deciduous woody vines of the folks Vitaceae. Grapes develop up in clusters of 6 to 300, and can be black, blue, golden, green, purple, red, pink, brown, peach or white. They can be eaten raw or used for producting jam, grape juice, jelly, wine and grape germ oil. Development of grapevines occurs in vineyards, and is called viticulture. One who studies and practises increasing grapes for wine is called a viticulturist. The leaves of the grape vine itself are painstaking safe to eat and are used in the production of dolmades.

Monday, November 26, 2007

Lighthouse of Alexandria

The Pharos of Alexandria was a large tower built in the 3rd century BC (between 285 and 247 BC) on the island of Pharos in Alexandria, Egypt to give out as that port's landmark, and later, its lighthouse.

With a height variously expected at between 115 and 150 meters (383 - 450 ft) it was among the tallest man-made structures on Earth for many centuries, and was recognized as one of the Seven Wonders of the World by Antipater of Sidon. It was the third big and tallest building after the two Great Pyramids (of Khufu and Khafra) for its whole life. Some scientists calculate approximately a much taller height exceeding 180 metres that would make the tower the tallest building up to the 14th century.

Monday, November 19, 2007

Traffic Claming

Traffic calming is a set of strategies used by urban planners and traffic engineers which aims to slow down traffic and get better safety for pedestrians and bicyclists, although some of these features can also be hazardous to cyclists. It is now comparatively common in Europe, especially Northern Europe; less so in North America.Traffic calming has conventionally been justified on the grounds of pedestrian safety and reduction of noise and local air pollution which are side effects of the traffic. However, it has become more and more apparent that streets have many social and recreational functions which are severely impaired by fast car traffic. For much of the twentieth century, streets were designed by engineers who were charged only with ensuring traffic flow and not with development other functions of streets. The rationale for traffic reassuring is now broadening to include designing for these functions.

Monday, November 12, 2007

Bareboat charter

A bareboat charter is an arrangement for the hiring of a boat, whereby no crew or provisions are contained as party of the agreement; instead, the people who rent the boat from the owner are responsible for taking care of such things.

There are legal differences between a bareboat charter and another types of charter arrangement, such as crewed or luxury yacht charter, commonly called time or voyage charters. In these charters the charterer can direct where the ship will go but the owner of the ship tells possession of the ship through its employment of the master and crew. In a bare-boat or demise charter, on the other hand, the owner gives possession of the ship to the charterer and the charterer retriew its own master and crew. The bare-boat charterer is sometimes known as a "disponent owner".

Monday, November 05, 2007

Banana boat

A banana boat (or a boat made of bananas), often referred to simply as a banana, is an unpowered recreational boat designed to be pulled by a bigger boat. Riders sit astride a big tube which is supported by two smaller tubes which provide balance and footrests, permit them to experience some of the thrill of moving fast and close to the water much more easily and safely than by water-skiing or surfing and they are therefore a popular ride for children. Many large motor yachts or luxury yachts have a banana as one of their onboard "toys", but any powered boat can pull a banana, and they are sometimes available as a commercial ride at holiday resorts. Most models seat middle of three and ten people. Two models with two seating tubes side by side are available. Banana boats are often yellow and are sometimes actually builted into the shape of a banana.

Monday, October 29, 2007

Types of boats

Airboat

Airboats are needlly flat-bottomed vessels propelled in a forward direction by an aircraft type propeller and powered by either an aircraft or automotive engine. The engine and propeller are covered in a protective metal cage that prevents objects, i.e., tree limbs, branches, clothing, beverage containers, wildlife from coming in contact with the whirling propeller, which could cause devastating falt to the vessel and traumatic injury to the operator and passengers.

The propeller gives a rearward column of air that propels the airboat forward. Steering is accomplished by forced air passing across vertical rudders. There must be a forceful airflow in order to the vessel to be steered. Airboats not have brakes and are incapable of traveling in reverse. Stopping and reversing direction are dependent upon operator/pilot/driver skill.

Monday, October 22, 2007

Parts of a boat

The roughly horizontal, but cambered structures spanning the hull of the boats are reffer to as the "deck". In a ship there are often many, but a boat is unlikely to have more than one. The similar but generally lighter structure which spans a raised cabin is a coach-roof. The "floor" of a cabin is properly known as the sole but is more likely to be called the floor. (A floor is properly, a structural member which ties a frame to the keelson and keel.) The underside of a deck is called the deck head. The keel is a lengthwise structural member to which the frames are constant one (sometimes referred to as a backbone). The vertical surfaces splitting the internal space are known as bulkheads. The front of a boat is known as the bow or prow. The rear of the boat is known as the stern. The right side of the boat is called starboard and the left side of the boat is called port.

Monday, October 15, 2007

ship
Usually a ship has enough size to carry its own boats, such as lifeboats, dinghies, or runabouts. A rule of thumb is "a boat can fit on a ship, but a ship can't fit on a boat". Consequently submarines are referred to as "boats", because early submarines were little enough to be carried aboard a ship in transit to distant waters. Other types of big vessels which are traditionally called boats are the Great Lakes freighter, the riverboat, and the ferryboat. Though big enough to carry their own boats and/or heavy cargoes, these examples are designed for operation on inland or protected coastal waters. Often local law and regulation will define the correct size (or the number of masts) which a boat requires to become a ship. Nautical meaning is related to sailors, particularly customs and practices at sea. Naval is the adjective pertaining to ships, step by step in common usage it has come to be more particularly associated with the noun "navy".

Monday, October 08, 2007

Boat
A boat is a watercraft designed to plane on, and provide transport over, water. However, boats such as the whaleboat were designed to be operated from a ship in an offshore environment. In Naval terms, a boat is small enough to be carried aboard another vessel (a ship). Boats that are notable exceptions to this concept due to their large size are the riverboat, narrowboat and ferryboat. These examples do, however, generally operate on inland , protected coastal waters. Modern submarines may also be referred to as boats but this is possibly due to the fact that the first submarines could be carried by a ship and were certainly not capable of making offshore passages on their own. Boats are may have military, other government, research, or commercial usage.

Monday, September 24, 2007

Water abstraction

Water abstraction, or water extraction, is the procedure of taking water from any source, either temporarily or permanently. Most water is used for irrigation or treatment to produce drinking water. Depending on the environmental legislation in the relevant country, controls may be located on abstraction to limit the amount of water that can be removed. Over abstraction can lead to rivers drying up or the level of groundwater aquifers reducing inappropriately. The science of hydrogeology is used to assess safe abstraction levels.

Monday, September 17, 2007

Pollination

Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the organization that contains the ovule (female gamete). The accessible part of the carpel is called a stigma in the flowers of angiosperms and a micro Pyle in gymnosperms. The study of pollination brings mutually many disciplines, such as botany, horticulture, entomology, and ecology. Pollination is significant in horticulture because most plant fruits will not develop if the ovules are not fertilized. The pollination process as communication between flower and vector was first addressed in the 18th century by Christian Konrad Sprengel.

Monday, September 10, 2007

Rainbow

Rainbows are optical and meteorological phenomena that reason of a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere. They take the form of a multicolored arc, with red on the external part of the arch and violet on the inner section of the arch. More rarely, a secondary rainbow is seen, which is a second, fainter arc, outside the primary arc, with colours in the differing order, that is, with violet on the outside and red on the inside.

A rainbow spans a permanent spectrum of colours. Traditionally, however, the chain of colours is quantized. The majority cited and remembered sequence, in English, is Newton's sevenfold red, orange, yellow, green, blue, indigo and violet. "Roy G. Biv" and "Richard of York Gave Battle In Vain" are admired mnemonics.

Though rainbows are bow-shaped in most cases, there are also phenomena of rainbow-colored flooring in the sky: in the shape of stripes, circles, or even flames.

Tuesday, September 04, 2007

Yachting

Yachting is a physical action connecting boats. It may be racing sailing boats, cruising to far-away shores, or day-sailing along a coast.
Whilst sailing's invention is prehistoric, racing sailing boats is supposed to have started in the Netherlands some time in the 17th century, whence it soon made its way to England where custom-built racing "yachts" began to emerge. In 1851, a challenge to an American yacht racing club in New York led to the beginning of the America's Cup, a regatta won by the New York Yacht Club awaiting 1983, when they finally lost to Australia II. For now, yacht racing continued to develop, with the development of recognised classes of racing yachts, from small dinghies up to huge maxi yachts.
These days, yacht racing and ship racing are common participant sports around the developed world, mainly where favourable wind conditions and access to reasonably sized bodies of water are available. Most yachting is conducted in salt water, but smaller craft can be - and are - raced on lakes and even huge rivers.
Whilst there are many different types of racing vessels, they can normally be separated into the larger yachts, which are larger and contain facilities for extensive voyages, and smaller harbour racing craft such as dinghies and skiffs.