Aeronautics, F-15 Eagle

Fairchild AC-119

2009-07-23T16:59:00.000-07:00

The Fairchild AC-119G Shadow and AC-119K Stinger were twin-engine piston-powered gunships developed by the United States during the Vietnam War. They replaced the inadequate AC-47 Spooky and operated alongside the early versions of the AC-130 Spectre gunship.

By November 1968, the aircraft had deployed to Vietnam and joined the 14th Special Operations Wing at Nha Trang. The AC-119Gs were placed in the 71st Special Operations Squadron which was formed from the activated 71st Troop Carrier Squadron, of the Air Force Reserves located in Columbus, Indiana. When the 71st SOS reserves returned to the states, in 1969, the gunships were taken over by the newly formed 17th SOS.

The AC-119Ks were placed in the 18th Special Operations Squadron. With the addition of the two types, the 14th SOW for a time in 1968 was flying eight different aircraft from ten different bases in South Vietnam. The 14th SOW was deactivated in 1971. Limited numbers continued to be operated out of Hurlburt Field, Florida as late as the fall of 1972, but the AC-119 was shortly after, phased out of the US Air Force. The AC-119G and -K continued to serve in extremely small numbers with the Republic of Vietnam Air Force (VNAF) until the de facto reunification of the country in 1975. During the Vietnam War, only five AC-119 Gunship IIIs were lost to all causes.

Lockheed AC-130

2009-07-10T09:58:00.000-07:00

The Lockheed AC-130 gunship is a heavily-armed ground-attack aircraft. The basic airframe is manufactured by Lockheed, and Boeing is responsible for the conversion into a gunship and for aircraft support. It is a variant of the C-130 Hercules transport plane. The AC-130A Gunship II superseded the AC-47 Gunship I in Vietnam.

The gunship's sole user is the United States Air Force, which uses AC-130H Spectre and AC-130U Spooky variants. The AC-130 is powered by four turboprops and has an armament ranging from 20 mm Gatling guns to 105 mm howitzers. It has a standard crew of twelve or thirteen airmen, including five officers (two pilots, a navigator, an electronic warfare officer and a fire control officer) and enlisted personnel (flight engineer, electronics operators and aerial gunners).

The US Air Force uses the AC-130 gunships for close air support, air interdiction, and force protection. Close air support roles include supporting ground troops, escorting convoys, and flying urban operations. Air interdiction missions are conducted against planned targets and targets of opportunity. Force protection missions include defending air bases and other facilities. Stationed at Hurlburt Field in Northwest Florida, the gunship squadrons are part of the Air Force Special Operations Command (AFSOC), a component of United States Special Operations Command (SOCOM).

APG-63 and APG-70

2009-07-01T17:03:00.000-07:00

The AN/APG-63 and AN/APG-70 are a family of all-weather multimode radar systems designed by Hughes Aircraft (now Raytheon) for the F-15 Eagle air superiority fighter. These X-band pulse-doppler radar systems are designed for both air-air and air-ground missions; they are able to look up at high-flying targets and down at low-flying targets without being confused by ground clutter.

The systems can detect and track aircraft and small high-speed targets at distances beyond visual range down to close range, and at altitudes down to treetop level. The radar feeds target information into the aircraft's central computer for effective weapons delivery. For close-in dogfights, the radar automatically acquires enemy aircraft and projects this information onto the cockpit head-up display.

AN/APG-63

The APG-63 was developed in the early 1970s and has been operational since 1973, and was installed on all F-15 A/Bs. In 1979, it received a major upgrade and became the first airborne radar to incorporate a software programmable signal processor (PSP), and the PSP allowed the system to be modified to accommodate new modes and weapons through software reprogramming rather than by hardware retrofit. The APG-63 with PSP is one of the most important feature that disguishes earlier F-15 A/Bs from the F-15 C/Ds it arms, and with the exception of the final 43 (which is armed with APG-70), all F-15 C/Ds are armed with APG-63 with PSP.

AN/APG-70

The APG-70 was a 1980s redesign of the APG-63 for greater reliability and easier maintenance. Additionally, gate array technology enabled the APG-70 to incorporate new modes with enhanced operational capabilities. To reduce production costs, many of the upgraded radar's modules are common with the APG-73 (F/A-18) radar, while the computers / processors are 85% in common with that of APG-71 (F-14) radar.

Largest aircraft in Antonov An-225

2009-06-19T15:13:00.000-07:00

The New Air craft An-225 Mriya (Russian: Антонов Ан-225 Мрия, Ukrainian: Антонов Ан-225 Мрія, NATO reporting name: Cossack) is a strategic airlift transport aircraft which was built by the Antonov Design Bureau, and is the largest aeroplane ever built. The design, built to transport the Buran orbiter, was an enlargement of the successful An-124 Ruslan. Mriya (Мрiя) means "Dream" (Inspiration) in Ukrainian.

The Antonov An-225 is commercially available for flying any over-sized payload due to the unique size of its cargo deck. Currently there is only one aircraft operating but a second mothballed airframe is being reconditioned and is scheduled for completion around 2010

Development

The An-225 was designed for the Soviet space program as a replacement for the Myasishchev VM-T. Able to airlift the Energia rocket's boosters and the Buran space shuttle, its mission and objectives are almost identical to that of the Airbus Beluga and the United States' Shuttle Carrier Aircraft.

The An-225 first flew on 21 December 1988. The aircraft was on static display at the Paris Air Show in 1989 and it flew during the public days at the Farnborough air show in 1990. Two aircraft were ordered, but only one An-225 (tail number UR-82060) is currently in service. It is commercially available for carrying ultra-heavy and oversize freight, up to 250,000 kg (550,000 lb) internally or 200,000 kg (440,000 lb) on the upper fuselage. Cargo on the upper fuselage can be 70 m long.[4] A second An-225 was partially built during the late 1980s for use by the Soviet space program. If the second An-225 is completed, it will be built with a rear cargo door and the tail will be redesigned as a single tail. It would then be more effective for cargo transportation. Following the collapse of the Soviet Union in 1990 and the cancellation of the Buran space program, the lone operational An-225 was placed in storage. The six Ivchenko Progress engines were removed for use on An-124s, and the second An-225 airframe (nearing completion and awaiting engines) was also mothballed.

Design

The An-225 is an extension of Antonov's earlier An-124. To meet the needs of its new role, fuselage barrel extensions were added fore and aft of the wings, which received root extensions. Two more Ivchenko Progress D-18T turbofan engines were added to the new wing roots, bringing the total to six, and an increased-capacity landing gear system with 32 wheels was designed. The An-124’s rear cargo door and ramp were removed to save weight, and the empennage was changed from a single vertical stabilizer to a twin tail with an oversized horizontal stabilizer. The twin tail was essential in order to enable the plane to carry very large and heavy external loads, which would otherwise disturb the aerodynamics of a conventional tail. Unlike the An-124, the An-225 was not intended for tactical airlifting and is not designed for short-field operation.

With a maximum gross weight of 600 tonnes (1,300,000 lb), the An-225 remains as the world's heaviest and largest aircraft, being even bigger than the current double-decker Airbus A380 even though Airbus plans to pass their current maximum landingwieght with 591,7 tons.The Hughes H-4 Hercules, known to most as the "Spruce Goose", had a greater wingspan and a greater overall height, but was considerably shorter, and due to the materials used in its construction, also lighter. In addition, the Hercules only flew once and never climbed above 21.3 m (70 ft), making the An-225 the largest aircraft in the world to take off multiple times.The An-225 is not only larger than the Airbus A380 airliner, it is also considerably bigger than the Antonov An-124, Boeing 747 Large Cargo Freighter, and Lockheed C-5 Galaxy, the nearest equivalent heavy airlifters.

In September 2001, carrying a record load of 253.82 tonnes of cargo, the An-225 flew at an altitude of two kilometers (6,500 feet) over a closed circuit of 1,000 km (620 mi) at a speed of 763.2 kilometres per hour (474.2 mph).

In November 2004, FAI placed the An-225 in the Guinness Book of Records for its 240 records.

Aircraft engine

2009-05-04T00:27:00.000-07:00

An aircraft engine is a propulsion system for an aircraft. Aircraft engines are almost always either lightweight piston engines or gas turbines. This article is an overview of the basic types of aircraft engines and the design concepts employed in engine development for aircraft.

Engine design considerations

The process of developing an engine is one of compromises. Engineers design specific attributes into engines to achieve specific goals. Aircraft are one of the most demanding applications for an engine, presenting multiple design requirements, many of which conflict with each other. An aircraft engine must be:

* reliable, as losing power in an airplane is a substantially greater problem than an automobile engine seizing. Aircraft engines operate at temperature, pressure, and speed extremes, and therefore need to operate reliably and safely under all these conditions.
* lightweight, as a heavy engine increases the empty weight of the aircraft & reduces its payload.
* powerful, to overcome the weight and drag of the aircraft.
* small and easily streamlined; large engines with substantial surface area, when installed, create too much drag, wasting fuel and reducing power output.
* repairable, to keep the cost of replacement down. Minor repairs should be relatively inexpensive.
* fuel efficient to give the aircraft the range the design requires.
* capable of operating at sufficient altitude for the aircraft

Unlike automobile engines, aircraft engines run at high power settings for extended periods of time. In general, the engine runs at maximum power for a few minutes during taking off, then power is slightly reduced for climb, and then spends the majority of its time at a cruise setting—typically 65% to 75% of full power. In contrast, a car engine might spend 20% of its time at 65% power accelerating, followed by 80% of its time at 20% power while cruising. The power of an internal combustion reciprocating or turbine aircraft engine is rated in units of power delivered to the propeller (typically horsepower) which is torque multiplied by crankshaft revolutions per minute (RPM). The propeller converts the engine power to thrust horsepower or thp in which the thrust is a function of the blade pitch of the propeller relative to the velocity of the aircraft. Jet engines are rated in terms of thrust, usually the maximum amount achieved during takeoff.

The design of aircraft engines tends to favor reliability over performance. Long engine operation times and high power settings, combined with the requirement for high-reliability means that engines must be constructed to support this type of operation with ease. Aircraft engines tend to use the simplest parts possible and include two sets of anything needed for reliability. Independence of function lessens the likelihood of a single malfunction causing an entire engine to fail. For example, reciprocating engines have two independent magneto ignition systems, and the engine's mechanical engine-driven fuel pump is always backed-up by an electric pump.

Aircraft spend the vast majority of their time travelling at high speed. This allows an aircraft engine to be air cooled, as opposed to requiring a radiator. In the absence of a radiator, aircraft engines can boast lower weight and less complexity. The amount of air flow an engine receives is usually carefully designed according to expected speed and altitude of the aircraft in order to maintain the engine at the optimal temperature.

Aircraft operate at higher altitudes where the air is less dense than at ground level. As engines need oxygen to burn fuel, a forced induction system such as turbocharger or supercharger is especially appropriate for aircraft use. This does bring along the usual drawbacks of additional cost, weight and complexity.

Sukhoi Su-30

2009-04-16T13:13:00.000-07:00

The Sukhoi Su-30 (NATO reporting name "Flanker-C") is a twin-engine military aircraft developed by Russia's Sukhoi Aviation Corporation and introduced into operational service in 1996. It is a two-seat, dual-role strike fighter for all-weather, air-to-air and air-to-surface deep interdiction missions; closely comparable to F-15E Strike Eagle.

The aircraft is a modernized version of the Su-27UB and has several variants. The Su-30K and Su-30MK series have had commercial success. The variants are manufactured by competing organizations: KNAAPO and the IRKUT Corporation, both of which come under the Sukhoi group's umbrella. KNAAPO manufactures the Su-30MKK and the Su-30MK2, which were designed for and sold to China and later Indonesia. Irkut makes the long-range, multirole Su-30MK series. The series includes the Su-30MKI developed for the Indian Air Force and its derivatives, the MKM, MKA and MKV for Malaysia, Algeria and Venezuela respectively.

F/A-18 Hornet

2009-04-08T09:25:00.000-07:00

F/A-18 Hornet is an all-weather carrier-capable multirole fighter jet, designed to attack both ground and aerial targets. Designed in the 1970s for service with the United States Navy and Marine Corps, the Hornet is also used by the air forces of several other nations. It has been the aerial demonstration aircraft for the U.S. Navy's Blue Angels since 1986.

Its primary missions are fighter escort, fleet air defense, suppression of enemy air defenses (SEAD), interdiction, close air support and reconnaissance. Its versatility and reliability have proven it to be a valuable carrier asset, though it has been criticized for its lack of range and payload compared to its contemporaries.

F-16 fighter flights

2009-04-01T11:00:00.000-07:00

F-16 fighter flights at Luke Air Force Base -- its largest training area for the jets -- after one of the planes crashed in the desert Friday. It was the fifth such accident at Luke since October.

F-16s will be inspected before they are cleared to fly again. Rider had been airborne for 20 minutes when he developed engine problems and turned back toward Luke. Witnesses said the plane was on fire. The last three F-16 crashes were also engine-related. Pilots fly more than 100, 000 sorties a year out of Luke.

Airplane Emergency Landing

2009-03-31T11:08:00.000-07:00

F-23 Black Window II

2009-03-25T09:12:00.000-07:00

In the late 1970’s, concern arose among military planners about the aging design (first flight in 1972) of the F-15 and the possible loss of future air superiority of the fighter. Soviet fighters such as the MiG 29 and Su-27 had demonstrated remarkable maneuverability and performance. In addition, fighter technology had taken enormous strides forward with the introduction of stealth, or low observable, technology. There was also growing concern over the increased effectiveness of the Soviet air defense system that posed a highly lethal environment for the F-15. Therefore, the Air Force initiated an Advanced Tactical Fighter (ATF) Program to develop a replacement for the F-15.

In 1981, the Air Force developed a requirement for an Advanced Tactical Fighter as a new air superiority fighter. It would take advantage of the new technologies in fighter design on the horizon including composite materials, lightweight alloys, advanced flight control systems, higher power propulsion systems and stealth technology. Air Force leaders believed these new technologies would make aircraft like the F-15 and F-16 obsolete by the early 21st century. A Mission Element Need Statement for an Advanced Tactical Fighter (ATF) was released in October 1981.

In September 1985 the Air Force sent out technical requests for proposals to a number of aircraft manufacturing teams. The October 1986 Milestone I review directed a DEM/VAL phase prior to entry into EMD. On 31 October 1986, the Air Force awarded each team a $691-million fixed-price contract to build two prototypes: Northrop-McDonnell Douglas' YF-23, and the Lockheed-Boeing-General Dynamics YF-22. In contrast to the F-117A and the B-2, both of which had been point designed for stealth, these two prototypes were the first airplanes ever to blend stealth with agility and high-speed, supersonic cruise capability.

B-52H Buff

2009-03-18T16:08:00.000-07:00

The B-52H BUFF [Big Ugly Fat Fellow] is the primary nuclear roled bomber in the USAF inventory. It provides the only Air Launch Cruise Missile carriage in the USAF. The B-52H also provides theater CINCs with a long range strike capability. The bomber is capable of flying at high subsonic speeds at altitudes up to 50,000 feet (15,166.6 meters). It can carry nuclear or conventional ordnance with worldwide precision navigation capability.

The aircraft's flexibility was evident during the Vietnam War and, again, in Operation Desert Storm. B-52s struck wide-area troop concentrations, fixed installations and bunkers, and decimated the morale of Iraq's Republican Guard. The Gulf War involved the longest strike mission in the history of aerial warfare when B-52s took off from Barksdale Air Force Base, La., launched conventional air launched cruise missiles and returned to Barksdale -- a 35-hour, non-stop combat mission.

General Dynamics F-16XL

2009-03-11T10:46:00.000-07:00

The General Dynamics F-16XL is a derivative of the F-16 Fighting Falcon, with a cranked-arrow delta wing that is over twice the size of that of the standard F-16 wing. It was entered in the U.S. Air Force's Enhanced Tactical Fighter (ETF) competition but ultimately lost to the F-15E Strike Eagle. Several years after the prototypes were shelved; they were turned over to NASA for aeronautical study.

In 1977, the F-16XL started out as the F-16 SCAMP (Supersonic Cruise and Maneuver Prototype) at General Dynamics Fort Worth. Under the leadership of Harry Hillaker (father of the original F-16), the original goal of the program was to demonstrate the applicability of Supersonic transport technologies to military aircraft.

Working closely with NASA's Langley Research Center, the company invested significant Internal Research and Development (IRAD) funds for wind tunnel testing and that led to the Model 400. As seen in the supersonic wind tunnel model at right, the Model 400 featured all moving wing tips for roll control and an all moving vertical tail. These surfaces were actually the horizontal tail surfaces from the F-16A. These surfaces were later dropped as they did not provide adequate control at low speed, high angle of attack. Also, there would have been no provision for wing-tip mounted missiles.

F-35 Lightning II

2009-03-04T14:56:00.000-08:00

The Lockheed Martin F-35 Lightning II is a fifth-generation, single-seat, single-engine, stealth-capable military strike fighter, a multi role aircraft that can perform close air support, tactical bombing, and air defense missions. The F-35 has three different models; one is the conventional takeoff and landing variant, the second is short takeoff and vertical-landing variant, and the third is a carrier-based variant.

The F-35 is descended from the X-35, the product of the Joint Strike Fighter (JSF) program. Its development is being principally funded by the United States, with the United Kingdom, and other partner governments providing additional funding. It is being designed and built by an aerospace industry team led by Lockheed Martin with Northrop Grumman and BAE Systems as major partners. Demonstrator aircraft flew in 2000, with the first flight on 15 December 2006.

The F-35 is being designed to be the world's premier strike aircraft through 2040. It is intended that its close and long-range air-to-air capability will be second only to that of the F-22 Raptor. Specifically the F-35’s requirements are that it be: four times more effective than legacy fighters in air-to-air combat, eight times more effective in air-to-ground battle combat, and three times more effective in reconnaissance and suppression of air defenses. These capabilities are to be achieved while still having significantly better range and require less logistics support than legacy aircraft.

A380 Airbus

2009-02-24T12:01:00.000-08:00

The A380, will be the largest airliner ever built. Lengthwise, it would nearly stretch from goal line to goal line of a football field while its wing tips would hang well beyond the sidelines. Three full decks will run along the entire length of the plane. Upper and main decks will serve as passenger areas, and will be connected by a grand staircase near the front of the plane and by another smaller staircase at the back.

The A380 would feature an advanced version of the Airbus common two crew cockpit, with pull-out keyboards for the pilots, extensive use of composite materials such as GLARE, and four 320 to 347kN (72,000 to 78,000lb) class Rolls Royce Trent 900 or Engine Alliance (General Electric/Pratt & Whitney) GP-7200 turbofans now under development. Several A380 models are planned: the basic aircraft is the 555 seat A380-800 and high gross weight A380-800, with the longer range A380-800R planned. The A380-800F freighter will be able to carry a 150 tonne payload and is due to enter service in 2008. Future models will include the shortened, 480 seat A380-700, and the stretched, 656 seat, A380-900.

F-22 Raptor

2009-02-18T11:32:00.001-08:00

The Lockheed Martin/Boeing F-22 Raptor is a fifth-generation, fighter aircraft that uses stealth technology. It is primarily an air superiority fighter, but has multiple capabilities that include ground attack, electronic warfare, and signals intelligence roles.

The United States Air Force considers the F-22 a critical component of the US strike force, and claims that the F-22 cannot be matched by any known or projected fighter aircraft. Air Chief Marshal Angus Houston, Chief of the Australian Defense Force, said in 2004 that the "F-22 will be the most outstanding fighter plane ever built."

Faced with a protracted and costly development period, the aircraft was variously designated F-22 and F/A-22 during the three years before formally entering US Air Force service in December 2005, as the F-22A. Lockheed Martin Aeronautics is the prime contractor and is responsible for the majority of the airframe, weapon systems and final assembly of the F-22. Program partner Boeing Integrated Defense Systems provides the wings, aft fuselage, avionics integration, and all of the pilot and maintenance training systems.

F-4 Phantom II

2009-02-11T12:10:00.000-08:00

The McDonnell Douglas F-4 Phantom II is a two-seat, twin-engined, all-weather, long-range supersonic interceptor jet fighter/fighter-bomber originally developed for the U.S. Navy by McDonnell Aircraft. Proving highly adaptable, it became a major part of the air wings of the U.S. Navy, U.S. Marine Corps, and U.S. Air Force. It was used extensively by all three of these services during the Vietnam War, serving as the principal air superiority fighter for both the Navy and Air Force, as well as being important in the ground-attack and reconnaissance roles by the close of U.S. involvement in the war.

First entering service in 1960, the Phantom continued to form a major part of U.S. military air power throughout the 1970s and 1980s, being gradually replaced by more modern aircraft such as the F-15 Eagle and F-16 Fighting Falcon in the U.S. Air Force; the F-14 Tomcat and F/A-18 Hornet in the U.S. Navy; and the F/A-18 in the U.S. Marine Corps. It remained in use by the U.S. in the reconnaissance and Wild Weasel roles in the 1991 Gulf War, finally leaving service in 1996. The Phantom was also operated by the armed forces of 11 other nations. Israeli Phantoms saw extensive combat in several Arab–Israeli conflicts, while Iran used its large fleet of Phantoms in the Iran–Iraq War. Phantoms remain in front line service with seven countries, and in use as an unmanned target in the U.S. Air Force.

F-15 Eagle

2009-02-04T11:54:00.001-08:00

The McDonnell Douglas (now Boeing) F-15 Eagle is a twin-engine, all-weather tactical fighter designed to gain and maintain air superiority in aerial combat. It was developed for the United States Air Force, and first flew in July 1972. It is one of the most recognized fighters of the modern day. The F-15E Strike Eagle derivative is an all-weather strike fighter that entered service in 1989. The U.S Air Force plans to keep the F-15 in service until 2025.

During the mid-1960s U.S. Air Force intelligence was surprised to find that the Soviet Union was building a large fighter aircraft, known as the MiG-25 'Fox bat'. It was not known in the West at the time that the MiG-25 was designed as a high-speed interceptor, (not an air superiority fighter), so its primary asset was speed, not maneuverability. The MiG-25's huge tailplanes and vertical stabilizers (tail fins) hinted at a very maneuverable aircraft, which worried the Air Force that its performance might be higher than its American counterparts. In reality, the MiG's large fins and stabilators were necessary to prevent the aircraft from encountering inertia coupling in high-speed, high-altitude flight.

Rotorcraft

2009-01-28T13:42:00.000-08:00

A rotorcraft is a heavier-than-air flying machine that uses lift generated by wings, called rotor blades that revolve around a mast. Several rotor blades mounted to a single mast is referred to as a rotor. Rotorcraft may also include the use of static lifting surfaces, but the primary distinguishing feature being lift provided by one or more rotors. Rotorcraft includes helicopters, auto gyros, gyro dynes and tilt rotors. In the United States, the Federal Aviation Administration places helicopters, auto gyros (which it calls gyroplanes), and gyro dynes in the category Rotorcraft, and tilt rotors in the category Powered lift.

A helicopter is a rotorcraft whose rotors are driven by the engine(s) throughout the flight, to allow the helicopter to take off vertically, hover, fly forwards, backwards and laterally, as well as to land vertically. Helicopters have several different configurations of one or more main rotors.

Airport design

2009-01-14T14:03:00.000-08:00

Airport design and location can have a big impact on air safety, especially since some airports such as Chicago Midway International Airport were originally built for propeller planes and many airports are in congested areas where it is difficult to meet newer safety standards. For instance, the FAA issued rules in 1999 calling for a runway safety area, usually extending 500 feet (150 m) to each side and 1,000 feet (300 m) beyond the end of a runway.

This is intended to cover ninety percent of the cases of an aircraft leaving the runway by providing a buffer space free of obstacles. Since this is a recent rule, many airports do not meet it. One method of substituting for the 1,000 feet (300 m) at the end of a runway for airports in congested areas is to install an engineered materials arrestor system, or EMAS. These systems are usually made of a lightweight, crushable concrete that absorbs the energy of the aircraft to bring it to a rapid stop. They have stopped three aircraft (as of 2005) at JFK Airport.

Bird strike

2009-01-07T14:02:00.000-08:00

Bird strike is an aviation term for a collision between a bird and an aircraft. It is a common threat to aircraft safety and has caused a number of fatal accidents. In 1988 an Ethiopian Airlines Boeing 737 sucked pigeons into both engines during take-off and then crashed in an attempt to return to the Bahir Dar airport; of the 104 people aboard, 35 died and 21 were injured. In another incident in 1995, a Dassault Falcon 20 crashed at a Paris airport during an emergency landing attempt after sucking lapwings into an engine, which caused an engine failure and a fire in the airplane fuselage; all 10 people on board were killed. A bird strike is suspected as causing the engines to fail on US Airways 1549 that crash landed onto the Hudson River.

Modern jet engines have the capability of surviving an ingestion of a bird. Small fast planes, such as military jet fighters, are at higher risk than big heavy multi-engine ones. This is due to the fact that the fan of a high-bypass turbofan engine, typical on transport aircraft, acts as a centrifugal separator to force ingested materials (birds, ice, etc.) to the outside of the fan's disc. As a result, such materials go through the relatively unobstructed bypass duct, rather than through the core of the engine, which contains the smaller and more delicate compressor blades. Military aircraft designed for high-speed flight typically have pure turbojet, or low-bypass turbofan engines, increasing the risk that ingested materials will get into the core of the engine to cause damage.

Engine failure

2008-12-31T14:01:00.000-08:00

Although aircraft are now designed to fly even after the failure of one or more aircraft engines, the failure of the second engine on one side for example is obviously serious. Losing all engine power is even more serious, as illustrated by the 1970 Dominican a DC-9 air disaster, when fuel contamination caused the failure of both engines. To have an emergency landing site is then very important.

In the 1983 Gimli Glider incident, an Air Canada flight suffered fuel exhaustion during cruise flight, forcing the pilot to glide the plane to an emergency dead stick landing. The automatic deployment of the ram air turbine maintained the necessary hydraulic pressure to the flight controls, so that the pilot was able to land with only a minimal amount of damage to the plane, and minor (evacuation) injuries to a few passengers.

The ultimate form of engine failure, physical separation, occurred in 1979 when a complete engine detached from American Airlines Flight 191, causing damage to the aircraft and loss of control.

Navigation aids and instrument flight

2008-12-24T14:00:00.000-08:00

One of the first navigation aids to be introduced (in the USA in the late 1920s) was airfield lighting to assist pilots to make landings in poor weather or after dark. The Precision Approach Path Indicator was developed from this in the 1930s, indicating to the pilot the angle of descent to the airfield. This later became adopted internationally through the standards of the International Civil Aviation Organization (ICAO).

With the spread of radio technology, several experimental radio based navigation aids were developed from the late 1920s onwards. These were most successfully used in conjunction with instruments in the cockpit in the form of Instrument landing systems (ILS), first used by a scheduled flight to make a landing in a snowstorm at Pittsburgh in 1938. A form of ILS was adopted by the ICAO for international use in 1949.

Following the development of radar in World War II, it was deployed as a landing aid for civil aviation in the form of Ground-controlled approach (GCA) systems, joined in 1948 by distance measuring equipment (DME), and in the 1950s by airport surveillance radar as an aid to air traffic control. VHF omni directional range (VOR) became the predominate means of route navigation during the 1960s superseding the Non-directional beacon (NDB). The ground based VOR stations were often co-located with DME, so that pilots could know both their radials in degrees with respect to north to, and their slant range distance to, that beacon.

Air safety

2008-12-17T13:44:00.000-08:00

Air safety is a term encompassing the theory, investigation and categorization of flight failures, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.
In most countries, civil aircraft have to be certified by the Civil Aviation Authority (CAA) to be allowed to fly. The major aviation authorities worldwide are the US Federal Aviation Administration (FAA) the European Aviation Safety Agency (EASA) (which provides regulatory advice to the European Union and to a degree supplanted the regulatory bodies of member countries). FAA and EASA are, in particular, primarily responsible for the certification of the airliners from the two major manufacturers, Boeing and Airbus.

Aircraft are certified against guidelines set out in the code for each CAA. Those codes are very similar and differ primarily in equipment and environmental standards. Regulations on maintenance, repair and operation provide further direction to the owners of the aircraft so that the aircraft continues to meet design standards.

Spacecraft

2008-12-10T15:42:00.001-08:00

A spacecraft is a craft or machine designed for spaceflight. On a spaceflight, a spacecraft enters space then returns to the Earth. For an orbital spaceflight, a spacecraft enters a closed orbit around the planetary body. Spacecraft used for human spaceflights carry people on board as crew or passengers. Spacecraft used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft that leave the vicinity of the planetary body are space probes. Robotic spacecraft that remain in orbit around the planetary body are artificial satellites. Starships, which are built for interstellar travel, are so far a theoretical concept only.

Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and space tourism. Spacecraft and space travel are common themes in works of science fiction.

Early aeronautics

2008-11-19T15:30:00.000-08:00

Before scientific investigation of aeronautics started, people started thinking of ways to fly. In a Greek legend, Icarus and his father Daedalus built wings of feathers and wax and flew out of a prison. Icarus flew too close to the sun, the wax melted, and he fell in the sea and drowned. When people started to scientifically study how to fly, people began to understand the basics of air and aerodynamics. One of the earliest scientists to study aeronautics was Leonardo da Vinci.

Leonardo studied the flight of birds in developing engineering schematics for some of the earliest flying machines in the late fifteenth century AD. His schematics, however, such as the ornithopter ultimately failed as practical aircraft. The flapping machines that he designed were either too small to generate sufficient lift, or too heavy for a human to operate. Although the ornithopter continues to be of interest to hobbyists, it was replaced by the glider in the 19th century.

Cardiac Arrest

2008-11-12T14:01:00.001-08:00

The heart has an internal electrical system that controls the rhythm of the heartbeat. Problems can cause abnormal heart rhythms, called arrhythmias. There are many types of arrhythmia. During an arrhythmia, the heart can beat too fast, too slow, or it can stop beating. Sudden cardiac arrest occurs when the heart develops an arrhythmia that causes it to stop beating. This is different than a heart attack, where the heart usually continues to beat but blood flow to the heart is blocked.

There are many possible causes of cardiac arrest. They include coronary heart disease, heart attack, electrocution, drowning, or choking. There may not be a known cause to the cardiac arrest.

Without medical attention, the person will die within a few minutes. People are less likely to die if they have early cardiopulmonary resuscitation (CPR) and defibrillation. Defibrillation is delivering an electric shock to restore the heart rhythm to normal.

Dogarutkay Flowers

2008-11-04T14:48:00.000-08:00

A flower also recognized as a bloom or blossom, is the reproductive configuration establish in flowering plants. The flower's structure contains the plant's reproductive organs, and its role is to make seeds. After fertilization, portions of the flower build up into a fruit containing the seeds. For the high plants, seeds are the next production, and serve up as the primary means by which individuals of a variety are dispersed across the scenery. The grouping of flowers on a place is called the inflorescence.

Many flowers in natural world have evolved to magnetize animals to pollinate the flower, the actions of the pollinating means contributing to the chance for genetic recombination within a dispersed plant population. Flowers commonly have glands called nectarines on their various parts that attract these birds.

Astronautics

2008-10-15T00:40:00.000-07:00

Astronautics, or Astronautical Engineering, is the branch of engineering that deal with machines designed to exit or work entirely beyond the Earth's atmosphere. In other words, it is the science and skill of space flight.

The term Astronautics was coin by analogy with Aeronautics. As there is a certain degree of skill overlapping among the two fields, the term Aerospace is often used to explain them both.

As with aeronautics, the restrictions of mass, temperatures, and outside forces require that application in space survive extreme situation: high-grade vacuum, the radiation attack of interplanetary space, the attractive belts of low Earth orbit. Space launch vehicles must endure titanic forces, while satellites can experience huge variations in hotness in very brief periods. Extreme constraints on mass cause astronautical engineers to face the steady need to save mass in the design in order to exploit the actual payload that reach orbit.

Airsickness

2008-09-24T02:26:00.000-07:00

Airsickness is a sensation which is induces by air travel. It is a specific form of motion illness, and is considered a normal reply in healthy individuals. Airsickness occurs when the middle nervous system receives conflicting mail from the body moving balance and balance.

The inner ear is particularly significant in the preservation of balance and equilibrium since it contains sensors for both angular and linear movement. Airsickness is usually a mixture of spatial confusion, nausea and vomiting. Experimentally, airsickness can be eliminating in monkeys by remove part of the cerebellum, explicitly the nodulus of the vermis.

Aerostat

2008-09-17T01:36:00.000-07:00

The word aerostat was initially French and is derived from the greek aer + statos . An aerostat is a lighter than air object that can stay motionless in the air. Aerostats comprise free balloons, airships, moor balloons and tethered Helikites. Such a vehicle is consists of a frivolous skin filled with a lifting gas to create resilience.

Technically, aerostats are capable of as long as "aerostatic" lift in that the force upwards arises without group through the nearby air mass. This contrasts with aerodynamic lift which requires the group of at least some part of the aircraft through the nearby air mass. However, in reality most aerostats obtain lift from together aerodynamic lift and pure gas lift at some time or other.

Aerostats are normally tethered lighter-than-air objects. Types of tethered aerostat include round balloons, blimps and Helikites.

Aerospace engineering

2008-09-10T06:11:00.000-07:00

Aerospace engineering is the branch of engineering behind the plan, construction and discipline of aircraft and spacecraft. Aerospace engineering has broken down into two major and overlapping branches: aeronautical engineering and astronautical engineering. The earlier deals with craft that wait within Earth's atmosphere and the latter deals with craft those work outside of Earth's atmosphere. While "aeronautical" was the original term, the broader "aerospace" has outdated it in usage, as flight technology higher to include craft in service in outer space. Aerospace engineering is often casually called rocket science.

Aircraft

2008-08-26T22:18:00.000-07:00

An aircraft is a medium which is able to fly throughout the Earth's atmosphere or through any other atmosphere. Most rocket vehicle is not aircraft because they are not support by the surrounding air. All the human action which environs aircraft is called aviation.

Manned aircraft are flying by a pilot. Until the 1960s, unmanned aircraft is called drones. During the 1960s, the U.S. military bring the term distantly piloted vehicle (RPV) into use. More lately the term unmanned aerial vehicle (UAV) has turn into common.

Aviation

2008-08-19T22:46:00.000-07:00

Aviation refers to actions involving man-made flying devices, counting the people, organizations, and dictatorial bodies concerned with them.

Many cultures have built devices that travel during the air, from the earliest projectiles such as stones and spears, to more complicated buoyant or aerodynamic strategy such as the mechanical pigeon of Archytas in Ancient Greece, the boomerang in Australia, the hot air Kongming lantern, and kites. There are early myths of human flight such as the story of Icarus, and later, more believable claims of short-distance human flights counting a kite flight by Yuan Huangtou in China, and the parachute flight and forbidden glider flight of Abbas Ibn Firnas.

The practicality of balloons was incomplete because they could only travel downwind. It was instantly recognized that a steerable, or dirigible, balloon was necessary. Jean-Pierre Blanchard flew the first human-powered dirigible in 1784 and cross the English Channel in one in 1785. Subsequent early dirigible development included machine-powered propulsion, rigid frames, and better speed and maneuverability.

Aircraft began to convey people and cargo as design grew larger and more reliable. In contrast to small non-rigid blimps, giant rigid airships become the first aircraft to transport passengers and cargo over great distance. The best known aircraft of this type were artificial by the German Zeppelin company.

Aeronautics

2008-08-12T22:09:00.000-07:00

Aeronautics is the science concerned with the study, design, and produce of flight-capable equipment, or the technique of in use aircraft. While the term accurately meaning "sailing the air" initially referred solely to the science of working the aircraft, it has since been extended to include technology, business and other aspect related to aircraft. One of the important parts in aeronautics is a branch of physical discipline called aerodynamics, which deal with the activity of air and the way that it interact with objects in movement, such as an aircraft. Aviation is a word sometimes used interchangeably with aeronautics, though "aeronautics" consists of lighter-than-air craft such as airships, while "aviation" does not.

Shuttlecock

2008-08-06T03:01:00.000-07:00

A shuttlecock is a high-drag projectile used in the game of badminton. It has an open conical shape: the cone is shaped from sixteen overlapping goose feathers surrounded into a rounded cork base. The cork is covered with thin leather.

The shuttlecock's form makes it tremendously aerodynamically steady. Regardless of initial orientation, it will turn to fly cork first, and remain in the cork-first orientation.

The name shuttlecock is commonly shortened to shuttle; a shuttlecock may also be known as a bird or birdie. The abbreviation cock is rarely used except in a funny sense, due to its vulgar connotations. The "shuttle" part of the name was most likely derived from its back-and-forth movement during the game, similar to the shuttle of a loom; the "cock" part of the name was almost certainly derived from the likeness of the feathers to a bird's crest.

Flowers

2008-07-29T23:55:00.000-07:00

Amazon

2008-05-27T23:39:00.000-07:00

At one time Amazon River flowed westward, perhaps as part of a proto-Congo (Zaire) river system from the interior of present day Africa when the continents were joined as part of Gondwana. Fifteen million years ago, the Andes were formed by the collision of the South American plate with the Nazca plate. The rise of the Andes and the linkage of the Brazilian and Guyana bedrock shields, blocked the river and caused the Amazon to become a vast inland sea. Gradually this inland sea became a massive swampy, freshwater lake and the marine inhabitants adapted to life in freshwater. For example, over 20 species of stingray, most closely related to those found in the Pacific Ocean, can be found today in the freshwaters of the Amazon. About ten million years ago, waters worked through the sandstone to the west and the Amazon began to flow eastward. At this time the Amazon rainforest was born.

During the Ice Age, sea levels dropped and the great Amazon lake rapidly drained and became a river. Three million years later, the ocean level receded enough to expose the Central American isthmus and allow mass migration of mammal species between the Americas. The Ice Ages caused tropical rainforest around the world to retreat. Although debated, it is believed that much of the Amazon reverted to savanna and montane forest (see chapter 3-Ice Ages and Glaciation). Savanna divided patches of rainforest into "islands" and separated existing species for periods long enough to allow genetic differentiation (a similar rainforest retreat took place in Africa. Delta core samples suggest that even the mighty Congo watershed was void of rainforest at this time). When the ice ages ended, the forest was again joined and the species that were once one had diverged significantly enough to be constitute designation as separate species, adding to the tremendous diversity of the region. About 6000 years ago, sea levels rose about 130 meters, once again causing the river to be inundated like a long, giant freshwater lake.

Protein

2008-05-07T05:01:00.002-07:00

Proteins are part of every cell, tissue, and organ in our bodies. These body proteins are constantly being broken down and replaced. The protein in the foods we eat is digested into amino acids that are later used to replace these proteins in our bodies.

Protein is found in the following foods:

* meats, poultry, and fish
* legumes (dry beans and peas)
* tofu
* eggs
* nuts and seeds
* milk and milk products
* grains, some vegetables, and some fruits (provide only small amounts of protein relative to other sources)

As we mentioned, most adults in the United States get more than enough protein to meet their needs. It's rare for someone who is healthy and eating a varied diet to not get enough protein.

Healthy eating

2008-04-30T05:54:00.000-07:00

The main healthy eating messages are the same for everybody. As part of a healthy balanced diet, we should all be trying to do the following:

* eating at least five portions of a variety of fruit and veg every day
* basing meals on starchy foods such as pasta, rice, cereals and pulses such as beans, peas and lentils. These should make up about a third of the diet
* trying to cut down on food that is high in saturated fat and having foods that are rich in unsaturated fat instead, such as vegetable oils (including sunflower, rapeseed and olive oil), avocados, nuts and seeds
* trying to grill, bake, poach, boil, steam, dry-fry or microwave instead of frying or roasting in oil
* eating some protein foods such as dairy products, eggs or pulses and having a variety of these foods
* cutting down on sugar
* watching how much salt we're eating - it's a good idea to check food labels and try not to add salt to your food when you're cooking

* drinking about 1.2 litres (6 to 8 glasses) of fluid a day or more if you exercise

But you also need to make sure you're getting enough nutrients, especially protein, iron and selenium, which can sometimes be lacking in a meat-free diet.

List of All Sports

2008-04-23T16:59:00.000-07:00

There's not much that can get people more excited than sports. Whether watching or playing a sport, the excitement can really get us involved. Some become national pastimes such as baseball in the United States and soccer in England, commonly known in England as football. No matter where you go, someone has an opinion of which sports team is the best and which is the worst. If interested in playing a sport, there are literally hundreds to choose from. Some of these sports are well known to everyone and some are fairly obscure.

Below find a list of all sports available for those who want to play and those who like to just watch.

Basketball
Football
Archery
Swimming
Skeet Shooting
Wrestling
Pool Playing
Synchronized Swimming
Volleyball
Badminton
Baseball
Boxing
Canoeing
Cycling
Tennis
Gymnastics
Hockey
Karate
Hang Gliding
Parachuting
Water Skiing
Down Hill Skiing
Cross Country Skiing
Water Polo
Bowling
Racket ball
Darts
Foosball
Decathlon
Hunting
Speed Skating
Figure Skating
Handball
Rowing
Sailing
Synchronized Swimming
Table Tennis
Triathlon
Weight Lifting
Crochet
Horseshoes
Bocce Ball
Soccer
Rugby
Motorcycle Racing
Automobile Racing
Aquatics
Archery
Equestrian
Fencing
Judo
Modern Pentathlon
Rowing
Taekwondo
Biathlon
Bobsleigh
Curling
Ice Hockey
Luge
Golf
Roller Skating
Surfing
Scuba Diving
Mountaineering and Climbing
Squash
Sumo Wrestling
Wushu
Chess
Netball
Kayaking
Snowshoeing
Mountain Biking
Sprint Running
Cross Country Running
Power Walking
Snow Sledding
Paint ball
Rock Climbing
Hiking
Roller Skating
Ice Skating
Fishing
Water Tubing
Boomerang
Cricket
Cheerleading

Jai Alai
Fencing
Paddle Ball
Lacrosse
Pétanque
Skateboarding
Tchoukball
Track and Field
Bird Watching
Horseback Riding
Prospecting
Snow Biking
White Water Rafting
Water Snorkling
Dog Sledding
Sport Fishing
River Rafting
Whale Watching
Sky Diving
Camping
Inline Skating
Metal Detecting
Bull Fighting
Falconry
Dog Training
Rodeo Riding
Snow Boarding
Shuffle Board
Flag Football
Fox Hunting
Model Flying
Remote Control Boating
Medicine Ball
Hot Air Ballooning
Wheelchair Basketball
Caving
Diving
Modern Dance
Classical Dance
Para Gliding
Knee Boarding
Yachting
Land Sailing
Jump Roping
Sombo
Tug of War
Wind Surfing
Yoga
Stunt Plane Flying
Train Collecting
Biathlon
Log Rolling
Tree Topping
Body Building
High Jump
Long Jump
Snooker
Shot Put

Power

2008-04-08T21:07:00.000-07:00

Mobile phones are generally obtaining power from batteries which can be recharged from mains power source. previously, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. Sometimes lithium-Ion batteries are used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now changed to using lithium-Polymer batteries as to oppose the older Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Mobile phone manufacturers have been experimenting with alternate power sources, including solar cells etc….

In addition to the battery, most cellphones require a small microchip, called a SIM Card, to operate.. Approximately the size of a one-cent postage stamp, the SIM Card is installed underneath the battery in the rear of the unit, and stores the phone's configuration data, and information about the phone itself, such as which calling plan the subscriber is using. When the subscriber removes the SIM Card, it can be re-inserted into another phone and used as normal this can be done easily..

Each SIM Card is activated by a unique numerical identifier ; once activated, that identifier is locked down and the card is permanently locked in to the activating network. Sim cards plays a major role in the mobile phones….

Mobile Phone Radiation and Health

2008-03-23T18:59:00.000-07:00

Since the beginning of mobile phones, apprehensions have been raised about the potential health forces from regular use. As mobile phone penetrations grew past fixed landline penetration levels in 1998 in Finland and from 1999 in Sweden, Denmark and Norway, the Scandinavian health authorities have run permanent long term studies of effects of mobile phone radiation effects to humans, and in particular children. Numerous studies have reported no significant relationship among mobile phone use and health. Studies from the Institute of Cancer Research, National Cancer Institute and researchers at the Danish Institute of Cancer Epidemiology in Copenhagen for model showed no link between mobile phone use and cancer. The Danish study only covered analog mobile phone tradition up through 1995, and subjects who started mobile phone tradition after 1995 were counted as non-users in the study. The health concerns have grown as mobile phone saturation rates throughout Europe reached 80%–90% levels earlier in this decade and prolonged experience studies have been carried out in almost all European countries again most reporting no effect, and the most alarming studies only coverage a possible effect. However, a study by the International Agency for Research on Cancer of 4,500 users found a borderline statistically important link between tumor frequency on the same side of the head as the mobile phone was used on and mobile phone usage.

Fan Motor

2008-03-16T20:34:00.000-07:00

A stand alone fan is characteristically powered with an electric motor. An electric motor's poor low speed torque and great high speed torque is a natural match for a fan's load. Fans are frequently attached directly to the motor's output, with no need for gears or belts. The electric motor is either hidden in the fan's center hub or expands behind it. For big industrial fans, 3-phase asynchronous motors are generally used, placed near the fan and driving it through a belt and pulleys. Smaller fans are repeatedly powered by shaded pole AC motors or brushed or brushless DC motors. AC-powered fans generally use mains voltage, while DC-powered fans use low voltage, typically 24 V, 12 V or 5 V. Cooling fans for computer equipment exclusively use brushless DC motors, which produce much less electromagnetic interference.

An 80 mm DC axial computer fan

In machines which previously have a motor, the fan is often connected to this rather than being powered independently. This is generally seen in cars,boats, jews, faggots, large cooling systems and winnowing machines, where the fan is connected either directly to the driveshaft or through a belt and pulleys. Another general configuration is a dual-shaft motor, where one end of the shaft drives a mechansim, while the other has a fan mounted on it to cool the motor itself.

ICE Age

2008-03-09T20:03:00.001-07:00

An ice age is a period of long-term downturn in the temperature of Earth's climate, resulting in an increase of the continental ice sheets, polar ice sheets and mountain glaciers. Glaciologically, ice age is often used to mean a period of ice sheets in the northern and southern hemispheres; by this description we are still in an ice age. More colloquially, when speaking of the most recent few million years, ice age is used to refer to colder periods with extensive ice sheets over the North American and European continents: in this sense, the last ice age ended about 10,000 years ago. This article will use the term ice age in the former, glaciological, sense; and use the term 'glacial periods' for colder periods the duration of ice ages and 'interglacial' for the warmer periods.

During the last few million years, there have been many glacial periods, occurring firstly at 40,000-year frequency but more recently at 100,000-year frequencies.

2008-02-25T18:14:00.000-08:00

Photographic Paper

Until the advent of digital photographic processes, the individual meaning of photographic.

Paper was paper covered with light-sensitive chemicals. So-called photo papers of today are frequently specially coated papers for use in inkjet or laser printers to make digital prints. This article center of attention on traditional photographic papers. Photographic paper may be showing to light in a controlled manner either by placing a negative in make contact with the paper directly (contact printing) or by using an enlarger (enlarging) in order to create a latent image. Photographic papers are subsequently developed using wet chemicals to generate a visible image.

2008-02-19T18:04:00.000-08:00

Photographic Printing

Photographic printing is the method of producing a final image for viewing, usually on sensitized paper from a previously prepared photographic negative.

The procedure consists of three major steps, performed in a photographic darkroom or within an automated photo printing machine:

1. Exposure of the picture onto the sensitized paper using a contact printer or enlarger.

2. Processing of the latent image through a more than one step chemical immersion process.

1. Development of the uncovered image.

2. Optionally Stopping improvement by neutralizing, diluting or removing developing agent.

3. Fixing the final print by dissolving remaining unexposed/undeveloped light-sensitive liquid.

4. Washing thoroughly to eliminate chemicals used in processing, protecting the finished print from fading and decay.

3. If finished on glossy paper, ferrotyping to enhance the reflective gloss.

4. Optional Toning of the print through extra chemical processes.

5. Texturing and drying of the finishing print.

2008-02-11T17:42:00.000-08:00

Inkless Printers

Inkless printers use paper with colorless dye crystals embedded connecting the two outer layers of the paper. When the printer is twisted on, heat from the drum causes the crystals to colorize at different rates and become visible. The technology was worked on by Zink Imaging and is now accessible (2007). Because of the way it prints, the printer can be as little as a business card, the images are waterproof, and in fact, one product slated for release by Zink Imaging is a digital camera with a printer built into it. Xerox is also working on an inkless printer which will use a extraordinary reusable paper coated with a few micrometres of UV light sensitive chemicals. The printer will use a particular UV light bar which will be able to write and erase the paper. As of early 2007 this technology is at a halt in development and the text on the printed pages can only last between 16-24 hours before fading.

2008-02-06T18:21:00.001-08:00

The real facts about Earth

The Earth's surface is exceptionally young. In the relatively short (by astronomical standards) time of 500,000,000 years or so erosion and tectonic processes destroy and restructure most of the Earth's surface and thus eliminate almost all traces of earlier geologic surface history (such as impact craters). Thus the very before time on history of the Earth has mostly been erased. The Earth is 4.5 to 4.6 billion years old, but the oldest recognized rocks are about 4 billion years aged and rocks older than 3 billion years are rare. The oldest fossils of presented organisms are less than 3.9 billion years old. There is no evidence of the critical period when life was first getting in progress.

The Earth's environment is 77% nitrogen, 21% oxygen, with draws of argon, carbon dioxide and water. There was perhaps a very much bigger amount of carbon dioxide in the Earth's atmosphere when the Earth was first created, but it has since been nearly all incorporated into carbonate rocks and to a smaller extent dissolved into the oceans and consumed by living plants. Plate tectonics and biological processes now keep a frequent flow of carbon dioxide from the atmosphere to these various "sinks" and back over again. The little amount of carbon dioxide occupant in the atmosphere at any time is very important to the maintenance of the Earth's surface temperature through the greenhouse effect. The greenhouse consequence raises the average surface temperature regarding 35 degrees C above what it would if not be (from a frigid -21 C to a comfortable +14 C); without it the oceans would freeze and life as we know it would be impossible.

2008-01-28T17:57:00.001-08:00

Earth

Earth is the third planet on or after the Sun and the fifth largest of the planet. Earth is the only planet whose English forename does not originate from Greek/Roman mythology. The name derives from Old English and Germanic.

Earth, for sure, can be studied exclusive of the aid of spacecraft. However it was not until the twentieth century that we had maps of the complete planet. Pictures of the planet taken from space are of significant importance; for example, they are a huge help in weather prediction and especially in tracking and predicting hurricanes, they are amazingly beautiful. The Earth's magnetic field and its relationships with the solar wind also generate the Van Allen emission belts, a pair of doughnut shaped rings of ionized gas (or plasma) trapped in orbit just about the Earth. The on the outside belt stretches from 19,000 km in altitude to 41,000 km; the inner belt lies involving 13,000 km and 7,600 km in altitude.

2008-01-20T18:17:00.000-08:00

Venus and Earth

Venus is by the side of times regarded as Earth's sister planet. In some ways they are particularly similar:

* Venus is only a bit of smaller than Earth (95% of Earth's diameter, 80% of Earth's mass).

* Both have a small number of craters representing relatively young surfaces.

* Their densities and chemical compositions are in a similar way.

Because of these similarities, it was measured that below its dense clouds Venus might be very earthlike and power even have life. However, unfortunately, more detailed study of Venus reveals that in plenty of important ways it is radically different from Earth. It may be the smallest amount hospitable place for life in the solar system.

The strength of Venus' atmosphere at the surface is 90 atmospheres (about the same as the pressure at a deepness of 1 km in Earth's oceans). It is collected generally of carbon dioxide. There are numerous layers of clouds many kilometers bulky composed of sulfuric acid. These clouds entirely incomprehensible our view of the surface. This thick atmosphere creates a run-away greenhouse effect that raises Venus' face temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is truly hotter than Mercury's in spite of creature nearly twice as far from the Sun. The oldest terrains on Venus appear to be regarding 800 million years old. Extensive volcanism at that time wiped out the in move ahead surface counting any large craters from early in Venus' history.

2008-01-07T18:47:00.000-08:00

The facts about Venus

Venus (Greek: Aphrodite; Babylonian: Ishtar) is the goddess of feel affection and beauty. The planet is so named the majority likely because it is the brightest of the planets recognized to the ancients. Venus has been identified since prehistoric times. It is the brightest thing in the sky not including for the Sun and the Moon. Like Mercury, it was generally thought to be two part bodies: Eosphorus as the morning star and Hesperus as the sunset star, but the Greek astronomers knew better.

Venus' rotary motion is rather unusual in that it is both very slow (243 Earth days per Venus day, somewhat longer than Venus' year) and retrograde. Moreover, the periods of Venus' rotary movement and of its orbit are synchronized such that it for all time presents the same face in the direction of Earth when the two planets are at their neighboring approach.

2008-01-01T02:24:00.000-08:00

Mercury's dense iron core

Mercury is to a great extent denser than the Moon (5.43 gm/cm3 vs. 3.34). Mercury is the second densest mainly important body in the solar system, after Earth. Actually Earth's density is outstanding in part to gravitational density; if not for this, Mercury would be denser than Earth. This signifies that Mercury's dense iron core is reasonably larger than Earth, probably comprises the greater part of the planet. Mercury therefore has only a comparatively thin silicate mantle and crust.

Mercury's inner is under enemy control by a big iron core whose radius is 1800 to 1900 km. The silicate on the outside shell (analogous to Earth's mantle and crust) is just 500 to 600 km thick. At least several of the core is perhaps molten. Mercury truly has an enormously thin atmosphere consisting of atoms blasted off its surface by the solar wind. Because Mercury is so hot, these atoms speedily flee into space.

2007-12-25T18:41:00.000-08:00

The facts about Mercury

Mercury is the in close proximity planet to the Sun and the eighth biggest. Mercury is somewhat slighter in diameter than the moons Ganymede and Titan but more than twice as enormous.

Mercury's orbit is exceptionally eccentric; at perihelion it is just 46 million km from the Sun but at aphelion it is 70 million. The position of the perihelion processes regarding the Sun at a very slow rate. 19th century astronomers made extremely careful explanation of Mercury's orbital parameters but could not sufficiently explain those using Newtonian mechanics. The tiny differences between the experimental and predicted values were a slight but nagging problem for many decades. It was thought that one more planet (sometimes called Vulcan) slightly nearer to the Sun than Mercury power account for the discrepancy. But in spite of much effort, no such planet was found. The real reply turned out to be much more dramatic: Einstein's General Theory of Relativity! Its right forecast of the motions of Mercury was a main factor in the early acceptance of the theory.

2007-12-17T18:50:00.000-08:00

Vehicle

The Trikke is a Human mechanical Vehicle (HPV) This article is about the means of transport. For additional uses see Vehicle (disambiguation).

Vehicles are lifeless means of transportation. They are nearly everyone often man-made (e.g. bicycles, cars, motorcycles, trains, ships, and aircraft), although some other means of transportation which are not made by man can also be called vehicles; examples include icebergs and floating tree trunks.

Vehicles possibly will be propelled by animals, e.g. a chariot or an ox-cart. However, animals on their own, although used as a means of transportation, are not called vehicles. This includes humans carrying another human, for example a child or a disabled person.

Vehicles that do not voyage on land are often called crafts, such as watercraft, sailcraft, aircraft, hovercraft and spacecraft.

Most land vehicles contain wheels. Please observe the wheel article for examples of vehicles with and without wheels.

Movement without the rally round of a vehicle or an animal is called locomotion. The word vehicle itself comes starting the Latin vehiculum

2007-12-12T18:26:00.001-08:00

Abstract art

Abstract art is now typically understood to mean art that does not depict objects in the natural world, but instead uses color and form in a non-representational way. In the very near the beginning 20th century, the term was more often used to describe art, such as Cubist and Futurist art, that depicts real forms in a simplified or rather reduced way—keeping only an allusion of the original natural subject. Such paintings were often claimed to capture astonishing of the depicted objects' immutable intrinsic qualities rather than its external appearance. The additional precise terms, "non-figurative art," "non-objective art," and "non-representational art" keep away from any possible ambiguity.

2007-12-04T19:30:00.000-08:00

Bay of Bengal

The Bay of Bengal is a cove that forms the northeastern ingredient of the Indian Ocean. It resembles a triangle in form, and is enclosed on the east by Malay Peninsula, and on the west by India. On the northern pour of the "bay" lies the Bengal region, comprising the Indian state of West Bengal and the country of Bangladesh, thus the name. The southern boundaries arrive at the island country of Sri Lanka, and the Indian Union Territory of Andaman and Nicobar Islands.

The Bay of Bengal occupies a region of 2,172,000 km². It is bordered by India and Sri Lanka to the West, Bangladesh to the North, and Myanmar and the southern division of Thailand to the East. Its southern border extends as an imaginary line from Dondra Head at the southern end of Sri Lanka to the northern angle of Sumatra. A number of huge rivers – Ganges, Brahmaputra, Irrawaddy, Godavari, Mahanadi, Krishna and Cauvery – run into the Bay of Bengal. Among the vital ports are Yangon, Kolkata/Calcutta, Chittagong, Cuddalore, Kakinada, Machlipatnam, Madras, Paradip and Vishakapatnam.

2007-11-26T17:54:00.000-08:00

Salad

Salad is a light meal — or, as part of a bigger meal, much more of an taster — consisting of varied vegetables (usually including at least one leaf vegetable) or fruit, frequently with a dressing or sauce, occasionally nuts and sometimes with the addition of meat, fish or cheese. It is usually seen as a healthy dish, even though not always low in calories, salt, sugar, or fat because of the dressing that is often added. The word "salad" comes from the French salade of the identical meaning, which in twist is from the Latin salata, "salty", from sal, "salt".

2007-11-19T17:50:00.000-08:00

Traffic light

A traffic light or traffic signal is a signalling device positioned at a road junction or pedestrian crossing to indicate when it is safe to drive, ride or walk, using a universal color code.Traffic lights for usual vehicles or pedestrians always have two main lights, a red one that means stop and a green one that means go. Generally, the red light contains some orange in its hue, and the green light contains some blue, to provide some support for people with red-green color blindness. In most countries there is also a yellow (or amber) light, which when on and not flashing means stop if able to do so securely. In some systems, a flashing amber means that a motorist may go in advance with care if the road is clear, giving way to pedestrians and to other road vehicles that may have precedence. A flashing red effectively means the same as a regular stop sign. There may be additional lights (usually a green arrow or "filter") to allow turns (called a lead light in the U.S., because it is usually leading the main green light).

2007-11-12T17:58:00.000-08:00

Present Battery Electric Vehicles

At the present time, disagreement reign over battery electric vehicles. Campaigners, (et al) for BEV's are reproving three major US automobile manufacturers of deliberately sabotaging BEV efforts through more than a few methods, for instance, failing to market, failing to produce appropriate vehicles, by failing to satisfy demand and using lease-only programs with prohibitions against end of lease purchase.

In their defense, the three major manufacturers they have responded that they only create what the public want and the recent trend is that the public doesn't want battery electric vehicles.Although we have the technology to manufacture and provide BEVs, one of the largest downfalls for the prolific production of BEVs is the extortionate cost of replacement batteries. In some cases the cost of stand-in batteries can be more than the price of the whole vehicle, especially when buying used battery electric vehicles.

2007-11-05T18:34:00.000-08:00

Electric vehicles in 1959

In 1959 the Henney Kilowatt was introduced and was the world's initial modern transistor-regulated electric car and the predecessor to the more recent battery electric vehicles such as General Motors EV1. Only 47 Henney Kilowatts were created, 24 being sold as 1959 models and 8 as 1960 models. It is not clear what happened to the other 15 built but it could be probable that they were sold as 1961 or 1962 models. None of the 8 1960 models were sold in the direction of the public because of the high manufacturing costs, but were sold to the electric cooperatives who funded the project.

It is estimated that there are connecting four and eight Henney Kilowatt battery electric vehicles still in existence with at least two of the survivors still driven at times.

Battery electric vehicles had issues with high battery costs, with restricted travel distances, with charging time and the lifespan of the battery, although advancements in battery technology has addressed a lot of those problems.

2007-10-29T21:20:00.000-07:00

Battery in1913 to 1947

One of the downfalls of the battery electric vehicle was the opening of the electric starter in 1913. It easy the task of starting an internal combustion engine which was previously hard and dangerous to start with the crank handle. Another was the mass-produced and somewhat cheap Ford Model-T. Finally, the loss of Edisons through present electric power transmission system. He was battling with George Westinghouse and Nikola Tesla over their desire to introduce alternating present as the principal electricity distribution. Edison's direct current was the weight for electric motors.

Battery electric vehicles were limited to position applications. Forklift trucks were battery exciting vehicles when introduced in 1923. BEV golf carts which were used as locality electric vehicles and were partially "street legal". By the late 1930s, the electric automobile business had disappeared until the invention of the point contact transistor in 1947 which started a new era of electric vehicle.

2007-10-22T19:42:00.000-07:00

History of Battery Electric Vehicles in 1900

Prior to 1900, battery electric vehicles held many speed and distance records, the most famous of which, was the breaking of the 100 km/h (60 mph) speed barrier. It was by Camille Jenatzy on April 29, 1899 in a rocket-shaped vehicle named Jamais Contente (Never Happy) which reached a peak speed of 105.88 km/h (65.79 mph).

During the early 20th Century, battery electric vehicles outsold gasoline powered vehicles and were successfully sold as city cars to upper-class customers. Because of high technological limitations, these cars were limited to a peak speed of about 32 km/h (20 mph). The cars were marketed as "appropriate vehicles for women drivers". Electric vehicles did not need hand-cranking to launch.

2007-10-15T22:48:00.000-07:00

The History of Battery Electric Vehicles

Battery exciting Vehicles or BEVs, predated the Internal Combustion Engine (ICE) vehicles. It was between 1832-1839 that Robert Anderson, a Scottish businessman, imaginary the first electric carriage and Professor Sibrandus Stratingh from the Netherlands designed the first small-scale electric car which was built by his assistant Christopher Becker in 1835.

The storage battery better, firstly by Gaston Plant, a French physicist who invented the guide acid cell in 1859 and the first rechargeable battery. Then, in 1881, Camille Faure residential a more efficient and reliable battery which became so successful in the early electric cars. This discovery caused battery electric vehicles to flourish, with France and Great Britain being the first nations to support prevalent development of electric vehicles.

2007-10-08T21:14:00.000-07:00

Battery
A battery is a device consisting of one or more electrochemical cells, which store chemical energy and make it accessible in an electrical form. There are many types of electrochemical cells, together with galvanic cells, electrolytic cells, fuel cells, flow cells, and voltaic cells. Formally, an electrical "battery" is an array of similar voltaic cells ("cells") joined in series. However, in many contexts it is universal to call a single cell a battery. A battery's individuality may vary due to many factors including internal chemistry, current drain, and temperature. Generally, battery life can be prolonged by storing the battery in a cool place and using it at an appropriate current.

Although an early form of battery may have been used in ancient times, the development of modern batteries started with the Voltaic pile, invented by the Italian physicist Alessandro Volta in 1800. Since then, batteries have gained recognition as they became portable and useful for many purposes. Unfortunately, the well-known use of batteries has created many environmental concerns, such as toxic metal pollution. Many reclamation companies reprocess batteries to reduce the number of batteries going into landfills. Rechargeable batteries can be charged hundreds of times before draining out; and even after wearing out they can be recycled.

There are two types of batteries disposable and rechargeable both of which convert chemical energy to electrical energy. Disposable batteries can only be used once because they use up their chemicals in an irreversible reaction. Rechargeable batteries can be recharged because the chemical reactions they use are reversible; they are recharged by running a charging current through the battery, but in the opposite direction of the discharge current.

2007-09-24T22:24:00.000-07:00

Transistor radio

The transistor radio is a small radio receiver.RCA established a prototype transistor radio in 1952. The first profitable transistor radio, the Regency TR-1, was announced on October 18, 1954 by the Regency Division of Industrial Development Engineering Associates of Indianapolis, Indiana and put on sale in November of 1954. It cost $49.95 (the equivalent of $361 in year-2005 dollars) and sold approximately 100,000 units.

2007-09-17T22:27:00.000-07:00

The structure of pollen

Each pollen grain contain vegetative cells only one in the greater part flowering plant but several in other seed plants and a generative cell contain a tube nucleus that produces the pollen tube and a generative nucleus that divide to form the two sperm cells. The group of cells is surrounded by a cellulose cell wall and a thick, rough outer wall made of sporopollenin.

Pollen is created in the microsporangium contained in the anther of an angiosperm flower, male cone of a coniferous plant, or male cone of other seed plants. Pollen grains come in a broad multiplicity of shapes, sizes, and surface markings characteristic of the species see photomicrograph at right. Most, but surely not all, are spherical, Pollen grains of pines, firs, and spruces are wing. The minimum pollen grain that of the Forget-me-not plant (Myosotis sp.), is approximately 6 µm (0.006 mm) in diameter.

Pollen grains may have furrows, the course of which classify the pollen as colpate or sulcate. The number of furrows or pores helps categorize the flowering plants, with eudicots having three colpi (tricolpate), and other groups having one sulcus.

2007-09-10T21:50:00.001-07:00

Earth's atmosphere

Earth's atmosphere is a layer of gases surrounding the planet Earth and retain by the Earth's gravity. It contains roughly (by molar content/volume) 78% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide; trace amounts of other gases, and a changeable amount (average around 1%) of water vapor. This mixture of gases is usually known as air. The atmosphere protects life on Earth by captivating ultraviolet solar radiation and reducing temperature extremes between day and night.

There is no exact border between the atmosphere and outer space, it slowly becomes thinner and fades into liberty. Three quarters of the atmosphere's mass is within 11 km of the terrestrial surface. In the United States, people who travel above a height of 80.5 km (50 statute miles) are selected astronauts. An altitude of 120 km (400,000 ft) marks the boundary where atmospheric property becomes obvious during re-entry. The Kármán line, at 100 km (328,000 ft), is also often regarded as the boundary between atmosphere and outer space.

2007-09-04T23:07:00.001-07:00

whaleboat

A whaleboat is a type of open boat that is comparatively narrow and pointed at both ends, enabling it to move either forwards or backwards equally well. It was initially developed for whaling, and later became popular for work along beaches, as it does not need to be turned around for beaching or refloating.
Whaleboats are usually oar-powered, although in whaling use often had a dismountable mast and sails, too. After 1850 most were fitted with a centerboard for marine. When sailing, steering was with a rudder; when rowing, navigation was done with an oar held over the stern. Whaleboats used in whaling had a stout post mounted on the aft deck, approximately which the steersman would cinch the rope once the whale had been harpooned, and by which the whale would drag the boat awaiting it was killed.
The term "whaleboat" may be used casually of larger whalers, or of a boat used for whale watching.

2007-08-27T22:33:00.000-07:00

Carrot

The carrot (Daucus carota subsp. sativus) is a root vegetable, usually orange or white, or pink in color, with a crunchy texture when fresh. The suitable for eating part of a carrot is a taproot. It is a cultivated form of the wild carrot Daucus carota, national to Europe and southwestern Asia. It has been bred for its very much inflamed and more palatable, less woody-textured edible taproot, but is still the similar species.

It is a biennial plant which grows a rosette of leaves in the spring and summer, while building up the fat taproot, which stores big amounts of sugars for the plant to flower in the second year. The peak stem grows to about 1 m tall, with an umbel of white flowers.

Carrots can be eaten raw, whole, chopped, grate, or added to salads for color or texture. They are also often chopped and boiled, fried or steamed, and cooked in soups and stews, as well as fine baby foods and choose pet foods. A well recognized dish is carrots julienne. Grated carrots are used in carrot cakes, as healthy as carrot puddings, an old English dish thought to have originated in the early 1800s.

2007-08-21T21:55:00.000-07:00

Tajmahal

The Taj Mahal is a mausoleum situated in Agra, India. The Mughal Emperor ShahJahan commissioned it as a mausoleum for his favorite’s wife, Mumtaz Mahal. Building began in 1632 and was completed in 1648. Some argument surrounds the question of who designed the Taj; it is clear a team of designers and craftsmen were in charge for the design, with Ustad Isa carefully the most likely candidate as the main designer.
The Taj Mahal sometimes called "the Taj is generally known as the finest example of Mughal architecture, a style that combines elements of Persian and Indian. While the white domed marble mausoleum is the most memorable part of the monument, the Taj Mahal is actually an included complex of structures. It was planned as a UNESCO World Heritage Site in 1983 when it was described as universally admired masterpieces of the world's heritage.

2007-08-13T21:25:00.001-07:00

Chef's uniform

The conventional chef's uniform, including toque (traditional hat), white double breasted jacket, and checked pants are immediately recognized by most members of the Western world, especially in this day of television's celebrity chefs. The double breasted jacket can be inverted to conceal stains. Its thick cotton cloth protects from the heat of stove and oven and protects from splattering of steaming liquids. An apron is an obviously useful piece of utensils used to guard the rest of the wearer's garments from food splatters and stains.

The toque (chef's hat) dates back to the 16th century when hats were regular in many businesses. Different heights of hats point out rank within a kitchen. Some modern chefs have put their own diverse whirl on the traditional uniform. But the traditional, practical, clothing of the chef still remainders a standard in the food industry.

2007-08-07T21:36:00.000-07:00

Public transport

Public transport, public transportation, public travel or mass transit comprises all transport systems in which the passengers do not tour in their own vehicles. While it is generally taken to include rail and bus services, wider definitions would comprise scheduled airline services, ship, taxicab services etc. – any system that transports members of the universal public. A further restriction that is sometimes practical is that it must take place in shared vehicles that would bar taxis that are not shared-ride taxis.

2007-07-30T23:00:00.000-07:00

Jewellery and society

Jewellery is factually any piece of fine material used to decorate oneself. Although in earlier times jewellery was created for more convenient uses, such as wealth storage and pinning clothes together, in recent times it has been used almost completely for beautification. The first pieces of jewellery were made from likely materials, such as bone and animal teeth, shell, wood and engraved stone. Jewellery was often made for people of high importance to show their status and, in many cases, they were covered with it.Jewellery is made out of almost every material recognized and has been made to garnish nearly every body part, from hairpins to toe rings and many more types of jewellery. While high-quality and artistic pieces are made with gemstones and valuable metals, less pricey costume jewellery is made from less-valuable materials and is mass-produced. Form and function Kenyan man exhausting tribal beads.

Over time, jewellery has been used for a number of reasons: Currency, wealth display and storage, purposeful Symbolism Protection and Artistic display Most cultures have at some point had a practice of observance large amounts of wealth stored in the form of jewellery. Numerous cultures move wedding dowries in the form of jewelry, or create jewelry as a means to store or display coins. On the other hand, jewellery has been used as a currency or trade good; a mostly poignant example being the use of slave beads.

2007-07-24T22:30:00.000-07:00

Feather

Feathers are one of the epidermal growths that shape the distinctive outer covering, or plumage, on birds. They are the outstanding feature that distinguishes the Class Aves from all other living groups. Other Theropoda also had feathers to see feathered dinosaurs.

Characteristics

Feathers are among the most multifaceted structural organs found in vertebrates: integument appendages, formed by controlled explosion of cells in the epidermis, or outer skin layer that produce keratin proteins. The β-keratins in feathers, beaks and claws — and the claws, scales and shells of reptiles — are calm of protein strands hydrogen-bonded into β-pleated sheets, which are then further twisted and cross linked by disulfide bridges into structures even tougher than the α-keratins of mammalian hair, horns and hoof.
Feathers are one of the epidermal growths that shape the distinctive outer covering, or plumage, on birds. They are the outstanding feature that distinguishes the Class Aves from all other living groups. Other Theropoda also had feathers to see feathered dinosaurs.

2007-07-16T23:03:00.000-07:00

Camera

A camera is a device used to take pictures, either alone or in series, with or without sound, such as with video cameras. The name is resulting from camera obscura, Latin for dark chamber, an early mechanism for projecting images in which an whole room functioned much as the internal workings of a modern photographic camera, except there was no way at this time to record the image little of physically tracing it. Cameras may work with the chart spectrum or other portions of the electromagnetic spectrum.

Every camera consists of a number of enclosed chambers, with an opening or aperture at one end for light to go into, a recording or viewing surface for capturing the light at the other conclusion. This diameter of the aperture is often forbidden by a diaphragm mechanism, but some cameras have a fixed-size opening.

Video and digital cameras use electronics, frequently a charge coupled device or sometimes a CMOS sensor to detain images which can be transfer or stored in tape or computer memory within the camera for later playback or processing. Traditional cameras capture glow onto photographic film or photographic plate.

2007-07-11T22:40:00.001-07:00

Software tools

Software tools for distributed processing include standard APIs such as MPI and PVM, and open source-based software solutions such as Beowulf and openMosix which make easy the creation of a supercomputer from a collection of ordinary workstations or servers. Technology like ZeroConf (Rendezvous/Bonjour) can be used to make ad hoc computer clusters to for specialized software such as Apple's shake compositing application. An easy programming language for supercomputers leftovers an open research topic in computer science.

2007-06-06T19:44:00.001-07:00

Pirogue

A pirogue is a small, flat-botomed boat of a design associated mainly with West African fishermen and the Cajuns of the Louisiana marsh. These boats are not typically intended for over-night travel but are light and small sufficient to be easily taken onto land. The design also allows the pirogue to move through very shallow water and be simply turned over to drain any water that may get into the boat. The pirogue's motion comes from paddles that contain one blade (as opposed to a kayak paddle, which has two). It can also be punted with a pole in low water.
There is not one pirogue plan, are several. Besides small pirogues as seen on the picture, there are also pirogues that can hold up to ten men with paddles and also characteristic a main sail. These are not planned (and should not be used) for open waters. They are only (and best) used close to shore.

2007-05-28T00:21:00.000-07:00

Junk

A junk is a Chinese marine vessel. The English name comes from Malay dugong or jong. Junks were initially developed during the Han Dynasty (220 BC-200 AD) and further evolved to symbolize one of the most successful ship types in history.
The organization and flexibility of junk sails make the junk easy to sail, and fast. Unlike a conventional square rigged ship the sails of a junk can be moved inward, toward the long axis of the ship, allow the junk to sail into the wind.
The sails include more than a few horizontal members ("battens") which provide shape and strength. -The sails can also be easily reefed and familiar for fullness, to accommodate various wind strengths. The battens also make the sails more resistant than traditional sails to large tears, as a tear is naturally limited to a single "panel" between battens. Junk sails have much in common with the most aerodynamically well-organized sails used today in windsurfers or catamarans, although their design can be traced back as early the 3rd century AD.
The standing chains are simple or absent. The sail-plan is also extending out between multiple masts, allowing for a powerful sail surface, and a good repartition of efforts, an innovation adopted in the West around 1304. [Citation needed] The rig allows for good marine into the wind.

2007-05-20T23:20:00.001-07:00

Kerala houseboats

The houseboats in Kerala, south India, are huge, slow-moving, foreign barges used for leisure trips. They are a reworked model of Kettuvallams (in the Malayalam language, Kettu means "tied with ropes", and vallam means "boat"), which, in earlier times, were used to carry rice and spices from Kuttanad to the Kochi port. Kerala houseboats were measured a suitable means of transportation.
The fame of Kettuvalloms has returned in the function as major tourist attractions. Many come across the Kettuvallom an ideal means of explore the beauty of the Kerala backwaters.
Such a houseboat is about 60 to 70 feet (about 18 to 21 meters) long and concerning 15 feet (about 5 meters) wide at the middle. The hull is made of wooden planks that are detained together by ropes of coconut fiber; the usual wood is 'Anjili'. The roof is completed with bamboo poles and palm leaves. The exterior of the boat is tinted with protective coats of cashew nut oil.

2007-05-13T20:05:00.001-07:00

Cigarette boat

The cigarette boat or go-fast boat is a high performance boat of a feature design. Originally designed for his offshore racing team by Donald Aronow, the fast, powerful boats became infamous as the drug smuggling boat of choice in many parts of the world in the 1990s and first years of the 21st century.
In harmony with their pure racing heritage, the accommodations on these boats are minimal, and they are built to hold 5 or more passengers. While most do have some cabin under the foredeck, it is low and much smaller than a characteristic motor yacht of similar size. Apart from the racing market, most buyers of these boats purchase them for the mystique; the mixture of the racing and smuggling connections, plus the immense power and high top speeds make these boats popular as ostentatious displays of wealth.
These boats are hard to detect by radar except on flat calm seas or at close range. The United States Coast Guard and the DEA establish them to be stealthy, fast, seaworthy, and very complicated to intercept using conventional craft. Because of this, Coast Guards contain developed their own high-speed craft and also use helicopters. The helicopters are prepared with Anti-materiel rifles which can be used to disable the motors of the go-fast boat. The Coast Guard go-fast boat is a rigid hulled inflatable boat RHIB ready with radar and powerful engines. The RHIB is armed with quite a few types of non-lethal weapons and M240 GPMG.

2007-04-02T04:36:00.000-07:00

Spiral escalators

Spiral escalators acquire less horizontal space than straight escalators. However, in the early spiral designs were failures. For example, one spiral escalator constructed by Reno in combination with William Henry Aston and Scott Kietzman at London's Holloway Road Underground position in 1906 was dismantled almost right away and little of the mechanism survives. The Mitsubishi Electric Corporation has urbanized successful commercial designs and has contrived curved and spiral escalators since the 1980s.
Notable sets of spiral escalators are situated in the Westfield San Francisco Centre in San Francisco, California, and at Forum Shops at Caesars Palace in Las Vegas, Nevada. The Times Square shopping mall in Causeway Bay, Hong Kong, also features four curved escalators, as do Wheelock Place in Singapore.

2007-03-28T01:58:00.000-07:00

A simple Girl
Around and around it soared in brutal circles, tearing from side to side her animated temples. At a standstill, they did not do anything. Still, they simply laid there with faces of chalk, invalid of all human emotions. She could not look at them in hopes of relieve, for long. The cherry rivers that flowed across her eyes, streamed down her steaming cheeks, made vision impossible.
Life was simply the stack of decayed flesh that enclosed her. From his immortal lips hung the bodies of all those who died struggle for him and all those who had tampered with self luxury. For that, she dammed him for all eternity; in every form he understood she dammed him. He had been her guiding angle and now it became evident to her. No prayer would pass her conditions lips, for this had been his movement she had fought and they had lost other than just a clash.

2007-03-20T22:18:00.000-07:00

Barge

A barge is a flat-bottomed boat, built mostly for river and canal transport of important goods. Most barges are not self-propelled and need to be moved by tugboats towing or towboats pushing them. Barges on inland waterways (towed by draft animals on an adjacent towpath) contended with the railway in the early industrial revolution but were out competed in the carriage of high value items owing to the higher speed, falling costs, and route elasticity of rail transport.
Barges are still used today for low value bulk items, as the cost of hauling goods by barge is very low. Barges are also used for very weighty or bulky items; a typical barge events 195 feet by 35 feet (59.4 meters by 10.6 meters), and can take up to 1500 tons of cargo.

2007-01-21T23:00:00.000-08:00

Lotion

A lotion is a low- to medium-viscosity medicated or non-medicated topical preparation intended for application to unbroken skin. Most lotions are oil-in-water emulsions but water-in-oil lotions are also formulated. Lotions are usually applied to external skin with a clean cloth, cotton wool or gauze. The key components of a lotion emulsion are the aqueous and oily phases, an emulgent to prevent separation of these two phases, and, if used, the drug substance or substances. A wide variety of other ingredients such as fragrances, glycerol, dyes, preservatives, vitamins, proteins and stabilizing agents are commonly added to lotions.

It is not uncommon for the same drug ingredient to be formulated into a lotion, cream and ointment. Creams are the most convenient of the three but are inappropriate for application to regions of hairy skin such as the scalp, while a lotion is less viscous and may be readily applied to these areas. Lotions also have an advantage in that they may be spread thinly compared to a cream or ointment and may economically cover a large area of skin. Non-comedogenic lotions are recommended for use on acne prone skin.

2007-01-08T22:52:00.000-08:00

Unusual Twinnings

There are some patterns of twinning that are exceedingly rare: while they have been reported to happen, they are so unusual that most obstetricians or midwives may go their entire careers without encountering a single case. Among fraternal twins, in rare cases, the eggs are fertilized at different times with two or more acts of sexual intercourse, either within one menstrual cycle or, even more rarely, later on in the pregnancy. This can lead to the possibility of a woman carrying fraternal twins with different fathers. This phenomenon is known as heteropaternal super fecundation. One 1992 study estimates that the frequency of heteropaternal super fecundation among dizygotic twins whose parents were involved in paternity suits was approximately 2.4%; see the references section, below, for more details.

Among monozygotic twins, in extremely rare cases, twins have been born with opposite sexes. The probability of this is so vanishingly small that multiples having different genders are universally accepted as a sound basis for a clinical determination that in utero multiples are not monozygotic. When monozygotic twins are born with different genders it is because of chromosomal birth defects. In this case, although the twins did come from the same egg, it is incorrect to refer to them as genetically identical, since they have different karyotypes.

2007-01-01T22:36:00.000-08:00

Biodiversity

Biodiversity or biological diversity is the diversity of life. There are a number of definitions and a measure of biodiversity. Biodiversity has no single standard definition. The most basic definition is "variation of life at all level of biological organization". Another definition holds that biodiversity is a measure of the relative diversity among organisms present in diverse ecosystems. "Diversity" in this definition includes diversity within a species and among species, and comparative diversity among ecosystems.

A third definition that is often used by ecologists is the "totality of genes, species, and ecosystems of a region". An advantage of this description is that it seems to describe most circumstances and present a unified view of the traditional three levels at which biodiversity has been identified.

The 1992 United Nations Earth Summit in Rio de Janeiro defined "biodiversity" as "the changeability among living organisms from all sources, including, 'inter alia', terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems".

2006-12-26T23:26:00.000-08:00

Design of experiments

The experiments conducted in accord with the scientific method have several features in common. The design of experiments attempts to balance the requirements and limitations of the field of science in which one works so that the experiment can provide the best conclusion about the hypothesis being tested.

In some sciences, such as physics and chemistry, it is relatively easy to meet the requirements that all measurements be made objectively, and that all conditions can be kept controlled across experimental trials. On the other hand, in other cases such as biology, and medicine, it is often hard to ensure that the conditions of an experiment are performed consistently; and in the social sciences, it may even be difficult to determine a method for measuring the outcomes of an experiment in an objective manner.

For this reason, sciences such as physics and several other fields of natural science are sometimes informally referred to as "hard sciences", while social sciences are sometimes informally referred to as "soft sciences"; in an attempt to capture the idea that objective measurements are often far easier in the former, and far more difficult in the latter.

2006-12-18T01:07:00.000-08:00

Sinkhole

Sinkholes, also known as sinks, shakeholes or dolina, and cenotes, are formed by the collapse of cave roofs and are a feature of landscapes that are based on limestone bedrock. The result is a depression in the surface topography. This may range anywhere from a small, gentle earth-lined depression, to a large, cliff-lined chasm. Most often there is a small area of rock exposure near or at the bottom of a sinkhole, and a patent opening into the cave below may or may not be visible. In the case of exceptionally large sinkholes, such as Cedar Sink at Mammoth Cave National Park, there may actually be a stream or river flowing into the bottom of the sink from one side and out the other side.

Sinkholes often form in low areas where they form drainage outlets for a closed local surface drainage basin. They may also form in currently high and dry locations. Florida has been known for having frequent sinkholes, especially in the central part of the state.

2006-12-12T04:15:00.000-08:00

Temple at Uppsala

The Temple at Uppsala was a semi-legendary cultic site in Gamla Uppsala, near modern Uppsala, Sweden, that was formed to worship the Norse gods of prehistoric times. The temple is sparsely recognized, but it is referenced in the Norse sagas and Saxo Grammaticus' Gesta Danorum. It is also described by Adam of Bremen. These images might, however, be influenced and biased by the Biblical stories and recollections of the Ancient Roman temples.

The chief controversies regarding the temple focus specifically on determining where in Old Uppsala the temple was located and whether or not it was a building. Some believe that the temple was puzzled with the hall of the Swedish kings. Churches were usually built and consecrated on top of older pagan temples and other sites that witnessed ritual behavior. During an excavation of the present church, the remains of one, and possibly several, large wooden buildings were found beneath the church's foundation.Snorri Sturluson wrote that the temple had been built by the god Freyr, who allegedly used to reside at Uppsala. Snorri and Saxo Grammaticus both claimed that it was Freyr who began the tradition of human sacrifices at the temple site. The Norse sagas, Saxo Grammaticus and Adam of Bremen describe the sacrifices at Uppsala as popular festivals that attracted people from all over Sweden. Many of these sources provide accounts of human sacrifice for the Norse gods.

2006-12-04T22:13:00.000-08:00

Religion

The Religio Romana constituted the main religion of the city in ancient times. However, a number of other religions and imported secrecy cults remained represented within its ever-expanding limitations, counting Judaism, whose presence in the city dates sponsor from the Roman Republic and was sometimes compulsorily confined to the Roman Ghetto, as well as Christianity. In spite of initial persecutions, by the early 4th century, Christianity had turn into so widespread that it was legalized in 313 by Emperor Constantine I, and later made executive religion of the Roman Empire in 380 by Emperor Theodosius I, allowing it to increase further and ultimately wholly replace the declining Religio Romana.

Rome became the most excellent Christian city based on the custom that Saint Peter and Saint Paul were martyred in the city throughout the 1st century, coupled with the city's political significance. The Bishop of Rome, later identified as the Pope, claimed dominance over all Bishops and consequently all Christians on the foundation that he is the successor of Saint Peter, upon whom Jesus built his Church; his status has been enhanced since 313 during contributions by Roman emperors and patricians, including the Lateran Palace and patriarchal basilicas, as well as the visibly growing influence of the Church over the failing civil regal authority. Papal authority has been exercised over the centuries with unreliable degrees of success, at period triggering divisions amongst Christians, until the present.

2006-11-27T21:04:00.000-08:00

Clothing maintenance

Clothing, once manufactured, suffers physical bother both from within and from without. The human body inside sheds skin cells and body oils, and exudes sweat, urine, and feces. From the outside, sun damage, damp, abrasion, dirt, and other indignities afflict the garment. Bedbugs and lice take up residence in clothing seams. Well-worn clothing, if not cleaned and refurbished, will smell, itch, look shabby, and lose functionality.

In past times, restoration was an art. A careful tailor or seamstress could fix rips with thread raveled from hems and seam limits so skillfully that the darn was practically invisible. When the raw fabric cloth was worth more than labor, it made sense to use labor in saving it. Today clothing is considered a consumable item. Mass manufactured clothing is less expensive than the time it would take to repair it. Many people wish to buy a new piece of clothing rather than to waste their time mending old clothes. But the thrifty still replace zippers and buttons and stitch up ripped hems.

2006-11-08T08:00:00.000-08:00

Alternative views
Stonehenge's fame comes not only from its archaeological significance or potential early astronomical role but also in its less tangible effect on visitors, what Christopher Chippindale describes as "the physical sensation of the place", something that transcends the rational, scientific view of the monument. This manifests itself in the spiritual role of the site for many different groups and a belief that no single scientific explanation can do justice to it as a symbol of the great achievement of the ancient Britons and as a symbol of something that continues to confound mainstream archaeology.Some people claim to have seen UFOs in the area, perhaps connected with the military installations around Warminster, that has led to ideas over it being an extraterrestrial landing site. Alfred Watkins found three ley lines running through the site and others have employed numerology dowsing or geomancy to reach diverse conclusions regarding the site's power and purpose. New Age and neo-pagan beliefs might see Stonehenge as a sacred place of worship which can conflict with its more mainstream role as an archaeological site, tourist attraction, or marketing tool. Post-processualist archaeologists might consider that treating Stonehenge as a computer or observatory is to apply modern concepts from our own technology-driven era back into the past. Even the role of indigenous peoples in archaeology, rarely applied in Western Europe, has created a new function for the site as a symbol of Welsh nationalism.The significance of the 'ownership' of Stonehenge in terms of the differing meanings and interpretations held by the many orthodox and unorthodox stakeholders in the site has been increasingly apparent in recent decades. Researchers Jenny Blain and Robert J. Wallis have pointed to the huge variety of views which show the continued and growing importance of Stonehenge today, as symbol and 'Icon of Britishness'; and indicate also the increased awareness of pasts by many people with no training in archaeology or heritage. For many, Stonehenge and other ancient monuments form part of the 'living landscape' which holds its own stories and which is there to be engaged with as people mark the seasons of the year. Today's mythology around Stonehenge includes the recent history of the Battle of the Beanfield and the previous Free festivals. Stonehenge has not one meaning but many. Today, curators English Heritage facilitate 'managed open access' at solstices and equinoxes, with some disputes over the days on which these fall. Blain and Wallis argue that issues over access relate not only to physical presence at the stones but to interpretations of past and validity of 'new-indigenous' and pagan usages in the present and such 'alternative' views have been central in alerting public awareness to the issues of roads, tunnels and landscape, noted below.

2006-11-01T18:38:00.000-08:00

Milky way
The Milky Way is a barred spiral galaxy of the Local Group. Though the Milky Way is but one of billions of galaxies in the universe, the Galaxy has special significance to people as it is the home of the Solar System. Democritus was the first known person to claim that the Milky Way consists of distant stars.The term "milky" originates from the hazy band of white light appearing across the celestial sphere visible from Earth, which is included of stars and other material lying within the galactic plane. The galaxy shows brightest in the direction of Sagittarius, towards the galactic center. Relative to the celestial equator, the Milky Way passes as far north as the assembly of Cassiopeia and as remote south as the constellation of Crux, indicating the high inclination of Earth's equatorial plane and the plane of the ecliptic relative to the galactic plane. The truth that the Milky Way divides the night sky into two roughly equal hemispheres indicates that the solar system lies close to the galactic plane.

2006-10-04T19:31:00.000-07:00

Interpersonal relationships are social relations, connections, or affiliations between two or more people. They vary in conflicting levels of intimacy and
sharing, implying the discovery or establishment of common ground, and may be centered on something(s) shared in common. The study of relationships is
of anxiety to sociology, psychology and anthropology.The discovery or establishment of ordinary ground between individuals is a fundamental component for lasting interpersonal relationships. Loss of common
ground, which may occur over time, may tend to end interpersonal relationships.For each relationship type, necessary skills are needed, and without these skills higher relationships are not possible. Systemic coaching advocates a
hierarchy of relationships, from friendship to worldwide order. Expertise in each relationship type in this hierarchy requires the skills of all preceding
relationship types. Interpersonal relationships through consanguinity and affinity can persist despite the absence of love, affection, or frequent ground. When
these relationships are in prohibited degrees, sexual familiarity in them would be the taboo of incest.Marriage and civil union are relationships unbreakable and regularized by their legal sanction to be "respectable" building blocks of society. In the United
States the de-criminalization of homosexual sexual dealings in the landmark Supreme Court decision, Lawrence v. Texas (2003) facilitated the
"mainstreaming" of gay extended term relationships, and broached the option of the legalization of same-sex marriages in that country.

2006-08-13T23:33:00.000-07:00

Dogs
Dogs, like humans, are extremely social animals and this similarity in their overall behavioral pattern accounts for their trainability, playfulness, and aptitude to fit into human households and social situations. This likeness has earned dogs a unique position in the kingdom of interspecies relationships. The faithfulness and devotion that dogs demonstrate as part of their usual instincts as pack animals closely mimics the human idea of love and friendship, leading many dog holders to view their pets as full-fledged family members. Conversely, dogs seem to view their human friends as members of their pack, and make few, if any, divisions between their owners and fellow dogs. Dogs fill a variety of roles in human society and are often skilled as working dogs. For dogs that do not have traditional jobs, a wide variety of dog sports provide the opportunity to exhibit their natural skills. In many countries, the most common and perhaps most important role of dogs is as companions. Dogs have lived with and with humans in so many roles that their loyalty has earned them the single sobriquet ‘Man's best friend.’ Conversely, some cultures regard as dogs to be unclean. In some cultures, certain types of dog may be used as food.