Sunday, 17 April 2011

Maglev Train

Maglev Train


What is a Maglev Train?


A Maglev Train is a system of transportation that suspends guides and propels vehicles.

How does it work using magnetic force?


In current electromagnetic suspension (EMS) systems, the train levitates above a steel rail while electromagnets, attached to the train, are oriented toward the rail from below. Magnetic attraction varies inversely with the cube of distance, so minor changes in distance between the magnets and the rail produce greatly varying forces.

In electrodynamics (the force of electricity in motion) suspension (EDS), both the rail and the train exert a magnetic field, and the train is levitated by the repulsive force between these magnetic fields. The magnetic field in the train is produced by either superconducting magnets, or by an array of permanent magnets. The repulsive force in the track is created by an induced magnetic field in wires or other conducting strips in the track.









Advantages


Maintenance Requirements of Electronic versus Mechanical Systems: Traditional rail is subject to the wear and tear of miles of friction on mechanical systems and increases exponentially with speed, unlike maglev systems. This basic difference is the huge cost difference between the two modes and also directly affects system reliability, availability and sustainability.

All-Weather Operations: Maglev trains currently in operation are not stopped, slowed, or have their schedules affected by snow, ice, severe cold, rain or high winds. This cannot be said for traditional friction-based rail systems. Also, maglev vehicles accelerate and decelerate faster than mechanical systems regardless of the slickness of the guide way or the slope of the grade because they are non-contact systems.

Efficiency: Due to the lack of physical contact between the track and the vehicle, maglev trains experience no rolling resistance, leaving only air resistance and electromagnetic drag, potentially improving power efficiency.

Noise: Because the major source of noise of a maglev train comes from displaced air, maglev trains produce less noise than a conventional train at equivalent speeds.



Countries that had introduced this technology


New York, United States 1968


In 1961, when he was delayed during rush hour traffic on the Throgs Neck Bridge, James Powell, a researcher at Brookhaven National Laboratory, thought of using magnetically levitated transportation to solve the traffic problem. Powell and BNL colleague Gordon Danby jointly worked out a Maglev concept using static magnets mounted on a moving vehicle to induce electrodynamics lifting and stabilizing forces in specially shaped loops on a guide way.

Hamburg, Germany 1979


Transrapid 05 was the first maglev train with long stator propelling force licensed for passenger transportation. In 1979, a 908 m track was opened in Hamburg for the first International Transportation Exhibition. There was so much interest that operations had to be extended three months after the exhibition finished, having carried more than 50,000 passengers. It was reassembled in Kassel in 1980.

Birmingham, United Kingdom 1984–1995


The world's first commercial automated maglev system was a low-speed maglev shuttle that ran from the airport terminal of Birmingham International Airport to the nearby Birmingham International railway station between 1984–1995. The length of the track was 600 meters, and trains "flew" at an altitude of 15 millimeters, levitated by electromagnets, and propelled with linear induction motors. It was in operation for nearly eleven years, but obsolescence problems with the electronic systems made it unreliable in its later years. One of the original cars is now on display at Railworld in Peterborough, while the RTV31 hover train vehicle is preserved on the Nene Valley Railway in Peterboroug.

Japan 1985


In Japan, there are two independently developed Maglev trains. One is HSST by Japan Airlines and the other, which is more well-known, is JR-Maglev by Japan Railways Group.

Vancouver, Canada, and Hamburg, Germany 1986-1988


In Vancouver, Canada (1986), the JR-Maglev was exhibited at Expo 86. Guests could ride the train along a short section of track at the fairgrounds. In Hamburg, Germany (1988), the TR-07 in international traffic exhibition (IVA88) performed Hamburg.

Berlin, Germany 1989–1991


In West Berlin, the M-Bahn was built in the late 1980s. It was a driverless maglev system with a 1.6 km track connecting three stations. Testing in passenger traffic started in August 1989, and regular operation started in July 1991. Although the line largely followed a new elevated alignment, it terminated at the U-Bahn station Gleisdreieck, where it took over a platform that was then no longer in use; it was from a line that formerly ran to East Berlin. After the fall of the Berlin Wall, plans were set in motion to reconnect this line. Deconstruction of the M-Bahn line began only two months after regular service began that was called Pundai project and was completed in February 1992.

What is the average speed of the maglev train and which country claimed the fastest moving one?


The average speed of the maglev train is 3720 mph and China (Shanghai) claimed the fastest moving one. Maglev vehicle achieved a Chinese record speed of 501 km/h at a non-commercial top speed. The journey was designed to connect Shanghai Pudong International Airport quickly to the outskirts of central Shanghai where passengers could interchange for their final destinations in the city centre.

Which is faster, F1 racing car or Maglev train?


A maglev train is faster. The fastest F1 racing car can only reach a speed of around 350 km/h while the fastest maglev train can reach a speed of 501 km/h.

Would you want the maglev train to be introduced in Singapore? If yes, why? If not, why not?


Yes, I would like to have a maglev train in Singapore as it can move in a faster than the normal MRT trains we have in Singapore and it creates lesser noise than the MRT trains.

Why this video was chosen amongst the many thousands online?



I think is video was chosen amongst the many thousands online because it provided relevant information about the maglev trains and it has a clear video too. The maglev train is useful to us because it is fast and convenient.

Source:


Thursday, 31 March 2011

Report on D

Sorry if the words are too small. Please zoom in if it is too small for you.

Wednesday, 16 March 2011

Online Lesson #4

Salmons

5 facts about Salmons

Largest and smallest
The largest species of salmon is the Chinook salmon, which is 1.5 m. The smallest species is the Masu or Sema salmon, which has a length of 71 cm.

Young Salmons
Newly hatched salmon with a yolk sac still attached are called alevins. When the yolk sac disappears, they are called fry. Until they are about a year old, they are called parr; 1- to 5-year-olds are called smoults.

Diet
Young salmon feed on microscopic animals and plants. As they get bigger, their diet includes insects and worms. By the time they are adults, they are eating small fish and crustaceans.

Migration

Salmon will hatch in freshwater, go to saltwater as smoults, and then return to freshwater in order to spawn and then die.

Misconception
Although legend claims that adult salmon return to the exact spot they were hatched from in order to spawn, there is no way to prove this.


Behavioural Adaptation
(Reproduction)
Salmons swim back to freshwater streams to spawn. They hurriedly swim 20 to 30 miles per day, without eating, against the current, leaping over waterfalls and rocks. The salmons will not stop till they reached their destination.

How does this adaptation benefit its predator?
After they spawn, they drift downstream and die. Their dead bodies provide food to many species of animals and also provide minerals to the trees.

Why is there a need for the females to spawn about 3000-15000 eggs in 1 run?
Just in case there is an inappropriate water flow. Appropriate water flow must continue after spawning; too much water may excavate the nest, while too little can reduce survivorship by raising water temperature and reducing oxygen flow. So, this is to prevent their species to extinct.

Online Lesson #3

Online Lesson #2

P.S. There are 2 slides.

Online Lesson #1

1. Identify the organism(s) that are producers?
The organisms are wheat, clovers and dandelion.
2. Identify the organism(s) that are consumers?
The organisms are the grasshoppers, mouse, rabbit, caterpillar, frog, snake, owl and hawk.
3. List some of the food chains by writing the organism's name and drawing a line that points to the next organism in the food chain.
Wheat –> Mouse –> Snake –> Owl
Clover –> Rabbit –> Hawk
Dandelion –> Caterpillar –> Frog –> Snake –> Owl
4. How many food chains can you find in the above food web?
There are 8 food chains in the above food web.