Tuesday, June 26, 2007

RISC (reduced instruction set computer)

In the mid-1980s to early-1990s, a crop of new high-performance RISC microprocessors appeared, which were initially used in special purpose machines and UNIX workstations, but have since become almost universal in all roles except the Intel-standard desktop.

The first commercial design was released by MIPS Technologies, the 32-bit R2000. The R3000 made the design truly practical, and the R4000 introduced the world's first 64-bit design. Opposing projects would result in the IBM POWER and Sun SPARC systems, respectively. Soon every major vendor was releasing a RISC design, including the AT&T CRISP, AMD 29000, Intel i860 and Intel i960, Motorola 88000, DEC Alpha and the HP-PA.

Market forces have "weeded out" many of these designs, leaving the PowerPC as the main desktop RISC processor, with the SPARC being used in Sun designs only. MIPS continue to supply some SGI systems, but are first and foremost used as an embedded design, notably in Cisco routers. The rest of the original crop of designs have either disappeared, or are about to. Other companies have attacked niches in the market, notably ARM, originally intended for home computer use but since focused at the embedded processor market. Today RISC designs based on the MIPS, ARM or PowerPC core are the vast majority of computing devices.

Saturday, June 23, 2007


A canoe is a small narrow boat, classically human-powered, but also commonly sailed. Canoes usually are pointed at both bow and stern and are normally open on top, but can be covered.
In its human-powered form, the canoe is propelled by the use of paddles, with the number of paddlers depending on the size of the canoe. Paddlers face in the direction of travel, either seated on supports in the hull, or kneeling directly upon the hull. In this way paddling a canoe can be contrasted with rowing, where the rowers face away from the direction of travel. Paddles may be single-bladed or double-bladed.
Sailing canoes are propelled by means of a variety of sailing rigs. Common classes of modern sailing canoes include the 5m² and the International 10m² Sailing canoes. The latter is otherwise known as the International Canoe, and is one of the fastest and oldest competitively sailed boat classes in the western world. The log canoe of the Chesapeake Bay is in the modern sense not a canoe at all, though it evolved through the enlargement of dugout canoes.

Sunday, June 17, 2007


A sandwich is a food item typically consisting of two pieces of leavened bread between which are laid one or more layers of meat, vegetable, cheese or jam, together with optional or traditionally provided condiments, sauces, and other accompaniments. The bread can be used as is, lightly buttered, or covered in a flavored oil to enhance flavor and texture. It is named after the 4th Earl of Sandwich.
Sandwiches are commonly carried to work or school in lunchboxes or brown paper bags to be eaten as the midday meal, taken on picnics, hiking trips, or other outings. In some parts of the world, they are also served in many restaurants as entrées, and are sometimes eaten at home, either as a quick meal or as part of a larger meal. When eaten as part of a full meal sandwiches are traditionally accompanied with such side dishes as a serving of soup (soup-and-sandwich), a salad (salad-and-sandwich), french fries/chips, potato chips/crisps and a pickle or coleslaw. A new trend appearing is making sandwiches into wraps, in which a tortilla is substituted for the bread. According to a recent court ruling in the United States, a sandwich must have two slices of bread and not one tortilla .

Monday, June 11, 2007

Urban archaeology

Urban archaeology is a sub regulation of archaeology specializing in the material past of towns and cities where long-term human habitation has often gone a rich record of the past. Humans generate waste. Large concentrations of humans manufacture large concentrations of waste. Feces, kitchen waste, broken objects etc. all need to be liable of. Small numbers of people can dispose of their waste locally without heartening vermin or endangering their health. Once people began to exist together in large numbers, around five thousand years ago, such methods began to become impractical. Material would be brought into these new settlements but would rarely be taken out again.

Wednesday, June 06, 2007

Krill fishery

Krill fishery is the commercial fishery of krill, small shrimp-like marine animals that live in the oceans world-wide. Estimates for how much krill there is vary wildly, depending on the methodology used. They range from 125–725 million tonnes of biomass globally. The total global harvest of krill from all fisheries amounts to 150 – 200,000 tonnes annually, mainly Antarctic krill (Euphausia superba) and North Pacific krill (E. pacifica).
Krill are rich in protein (40% or more of dry weight) and lipids (about 20% in E. superba). Their exoskeleton amounts to some 2% of dry weight of chitin. They also contain traces of a wide array of hydrolytic enzymes such as proteases, carbohydrases, nucleases and phospholipases, which are intense in the digestive gland in the cephalothorax of the krill.
Most krill is used as aquaculture feed and fish bait; other uses comprise livestock or pet foods. Only a small percentage is prepared for human consumption. Their enzymes are interesting for medical applications, an expanding sector since the early 1990s.