MAGLEV TRAIN

We have always thought of aeroplanes as the fastest mode of transportation. As it travels thousands of miles in an hour we do not mind the flight delays and also the risk in flying. There is no other alternative to planes that can travel such a great distance in minimum amount of time. Buses, cars, boats and even conventional trains seem to be too slow in comparison to planes.

Now a new transportation mode has occurred that can clearly compete with planes in both speed and safety. They are called MAGLEV trains. The full form and the basic working principle of MAGLEV is called magnetic levitation.

Magnetic Levitation
The principle of magnetic levitation is that a vehicle can be suspended and propelled on a guidance track made with magnets. The vehicle on top of the track may be propelled with the help of a linear induction motor. Although the vehicle does not use steel wheels on a steel rail they are still referred to as trains as by definition they are a long chain of vehicles which travel in the same direction. This is the definition of a MAGLEV train.




As the frictional parts are minimum in this type of technology, the MAGLEV trains are known to have more speed, smoothness and less sound.

Working of MAGLEV Train
The train will be floating about 10mm above the magnetic guiding track. The train will be propelled to move by the guide way itself. Thus, there is no need of any engine inside he train. The detailed working of MAGLEV train is shown in the figure below. The train is propelled by the changing in magnetic fields. As soon as the train starts to move, the magnetic field changes sections by switching method and thus the train is again pulled forward. The whole guide way is run by electromagnets so as to provide the magnetic effect.



Thus the power needed for the whole process is less when compared to a conventional electric train. Amongst the power used, only a little is used for the levitation process. But a higher percentage of power is needed to overcome air friction.

MAGLEV v/s Conventional Train
The main difference between both the trains is that conventional trains need steel wheels and a steel track for their movement and MAGLEV does not need wheels. They travel under the principle of electromagnetic suspension.

Another difference is in the engine used. MAGLEV trains do not need engines like conventional trains. The engine used for conventional trains provide power to pull a chain of compartments along steel tracks. In MAGLEV trains, the power to propel the train is provided by the magnetic fields created by the electric coils kept in the guidance tracks which are added together to provide huge power.

MAGLEV Track
The track along which the train moves is called the guide way. Both the guide way as well as the train’s undercarriage also have magnets which repel each other. Thus the train is said to levitate about 0.39 inches on top of the guide way. After the levitation is complete, enough power has to be produced so as to move the train through the guide way. This power is given to the coils within the guide way, which in turn produces magnetic fields, which pulls and pushes the train through the guide way.








The current that is given to the electric coils of the guide way will be alternating in nature. Thus the polarity of the coils will be changing in period. Thus the change causes a pull force for the train in the front and to add to this force, the magnetic field behind the train adds more forward thrust.

Commercial use of MAGLEV Trains
The first known commercial use of MAGLEV train was in the year 1984 in Birmingham, England, and the train was named MAGLEV itself. But due to less reliability, the train was stopped by 1994.
The most famous commercial MAGLEV train is the Shanghai MAGLEV train in Shanghai, China. The train can go in a top speed of 270 miles/hour with an average speed of 160 miles/hour.
Since these trains move on a cushion of air, there is no friction at all [except air friction]. The trains are also aerodynamically designed which enables them to reach great speeds like 300 miles/hour and so on. At 300 miles/hour you can travel from Rome to Paris in about 2 hours.
EMS and EDS Systems
Some of the greatest developers of the MAGLEV trains are Germany and Japan. Although the basic concepts used for the construction are the same, the prototypes used are different. German trains use electromagnetic suspension (EMS) system so as the bottom of the train is wrapped to a steel guide way. Thus levitation occurs between the electromagnets that are attached underneath the train and the guide way to about 1 centimetre. It also helps in keeping the train in levitation, when it is standing still. Such trains were tested to go on a maximum speed of about 300 miles/hour with passengers on-board.

In Japan, MAGLEV trains use a technology called electro-dynamic suspension (EDS) system, which causes the trains to move due to the repelling force of magnets. The main difference with EMS is that, the electromagnets used will be super cooled and superconducting. Such magnets are prone to conduct current even if there is no power supply. Thus EDS system helps to save more power than EMS system. But the cooling mechanism and thus the initial cost will be expensive.

In EDS systems, the levitation distance is almost 10 centimetres above the guide way. This distance will need the use of rubber tires for the initial lift-off speed of the train [up to 62 miles/hour]. Since the EDS system produces superconducting magnetic field, people having pacemakers will have to be guarded from magnetic fields.

Advantages of MAGLEV
The main advantage is maintenance. There is no contact between the guide way and the train which lessens the number of moving parts. Thus the components that wear out is little.
Another advantage is the reduction in noise. As there are no wheels running along there is no wheel noise. However noise due to air disturbance will still be there.
The next advantage is high speed. As there are no frictional contacts, the train is prone to have more speed.
Another advantage is that the guide way can be made a lot thicker in uphill places, after stations and so on. This will help in increasing the speed of the train further.
Disadvantages of MAGLEV
The initial cost of MAGLEV trains are highly costly. The guide paths are also supposed to be more costly than conventional steel railways.

Environmental Friendliness of MAGLEV Trains
MAGLEV trains are more environmentally friendly than other types of trains.  In terms of energy consumption maglev trains are slightly better off than conventional trains. As there is no wheel friction with the ground, the resistive force gradually increases in the air friction. Thus the energy efficiency difference between a MAGLEV train and a conventional train is of very small margin.

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The World’s Largest Fusion Reactor

Since, 1932, researchers have been successful in combining hot fusion with nuclei. Till then the concept of cold fusion was used and did not produce any satisfactory results. The research in hot fusion is still continuing and they have been successful in providing danger-free, very good potential energy source without producing much wastes.
Some of the main advantages of a fusion power plant is that they will not produce any high radioactive waste which will live for a long period. They cannot be used as a deadly weapon and cannot be subjected to meltdown. Thus, it is clear that hot fusion reactor is a very good energy producer when compared to other low efficient conventional methods.
In order to produce such a reactor, an international research and experimenting project was made by the name International Thermonuclear Experimental Reactor (ITER). Researchers at ITER have decided to build the world’s biggest and most efficient “tokamak” nuclear reactor. Tokamak refers to the device that uses a magnetic field to restrict the plasma inside a vessel. Thus the fusion reaction process is experimented inside this vessel. The plasma that is restricted inside the vessel with the help of magnetic field is composed of deuterium and tritium, and two isotopes of hydrogen. The radio waves and micro waves, along with the particle beams rise the temperature inside the vessel to as high as 270 million degrees Fahrenheit. This is the minimum temperature that is required to support the fusion process.
The inside schematic of an ITER Tokahama nuclear reactor is shown below.

The basic working of a reactor is given below.
Firstly, the fuel in the form of two hydrogen isotopes, deuterium and tritium is injected into the tokamak. The vessel will be filled with plasma, a huge mix of changed particles, as soon as an electric current heats the deuterium and tritium gases and ionizes them.The plasma produces high temperature heat as soon as radio waves, microwaves and high-energy deuterium particle react with it. This high temperature causes further reaction between deuterium and tritium and forms products like helium atom and a neutron.
Great care has to be taken in avoiding the plasma from touching the wall of the fusion reactor. Since it will have high temperatures, they may cause holes on the walls and hence leakage. To avoid this from happening, the charged particle is restricted in a magnetic field made from 39 superconducting poloidal, toroidal and central solenoid magnets positioned inside and outside the doughnut shaped vessel. Since the walls may also be affected from high energy neutrons, a 2 feet thick steel blanket lining is also coated around the wall.
When a tritium and deuterium nuclei react together they give away helium and a neutron. If the same process is carried out inside a tokamak fusion reactor, it would produce enormous heat (energy) that is more than enough to generate electricity by rotating a turbine.
The whole experiment is to be carried out in a place called Cadarache, the south of France. The researchers claim that this reactor will be the largest tokamak in the world, since it is capable of producing 500 megawatts of power.
But, they have clearly stated that the whole process will just be an experiment and thus, the reactor will not be used to produce electricity. After an outline of the whole experiment is made and the budget estimated, the work will start by 2019. If it turns out to be successful, a 2,000 to 4,000 megawatt producing power plant will be built by 2040!!
According to Richard Pitts, a scientist who is working on the project, the whole process is claimed to be very safe. He says that there will be no hazards or radiation leaks like what happened in Chernobyl and Fukoshima.
In order to carry out experiments, the researchers will have to face a lot of technical problems. Some of them are
The breeding of tritium is extremely difficult since the material is scarcely found anywhere on Earth. At any time, only 50 pounds of tritium is produced and it has a high decay rate. This scarcity is because the material is not naturally produced. But, there will not be any problem in producing deuterium as it not radio-active and it can be distilled from water. They can use the tritium used in other power plants, but if high-end experiments are to be carried out, they will have to produce their own supply. Neutrons from the fusion reaction could be used to convert a little of lithium into tritium.The inside schematic of an ITER Tokahama nuclear reactor is shown below.
According to Richard Pitts, a scientist who is working on the project, the whole process is claimed to be very safe. He says that there will be no hazards or radiation leaks like what happened in Chernobyl and Fukoshima.
In order to carry out experiments, the researchers will have to face a lot of technical problems. Some of them are:
The breeding of tritium is extremely difficult since the material is scarcely found anywhere on Earth. At any particular time only 50 pounds of tritium is produced and it has a high decay rate. This scarcity is because the material is not naturally produced. But, there will not be any problem in producing deuterium as it not radio-active and it can be distilled from water. They can use the tritium used in other power plants, but if high-end experiments are to be carried out, they will have to produce their own supply. Neutrons from the fusion reaction could be used to convert a little of lithium into tritium.
The researchers must also know which material can be used to build tokamak walls, as it could be easily worn down from the reaction with the by-products from the fusion reaction.
There could also occur maintenance problems as the workers inside the vessel could be affected by residual radioactivity. Thus, they will have to design robots that are capable of carrying small tasks like replacing faulty parts and so on
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‘Cling-Film’ Solar Cells – A New Revolution for Renewable Energy

Scientists from the Universities of Sheffield and Cambridge have started a new research that promises to produce cost-effective and highly efficient cling film solar cells. The idea was first published in the journal “Advanced Energy Materials”. According to them, these solar cells can also be produced with much ease. This has clearly become a great advancement in the field of renewable solar energy.
To carry out the tests, the ISI Neutron Source and Diamond Light Source at STFC Rutherford Appleton Laboratory in Oxfordshire were used.
Until now, two types of solar cell materials are being used – plastic and silicon. When it comes to manufacturing of the material, plastic is known to be much much cheaper. Due to the simple manufacturing process, they can also be produced in huge quantities. When molecules having complex mixtures are spread on to a surface, the molecules move away from one another and start to accumulate at the top and bottom of the layer. Thus, a highly efficient solar cell is produced. This same principle was used by researchers to prove that by using much better and cost less manufacturing methods, where flexible layers of material are deposited over large areas like cling-film, highly efficient solar cell structures can be produced.
These solar cells are known to be useful for both home use as well as industrial use and since it is very cheap, it can be manufactured on a high-scale. Instead of using high-end fabrication methods to manufacture a certain semi-conductor nanostructure, high number of printing could be used to produce nano-scale films of solar cells that are much thinner than the width of a human hair. Such films can be used to produce cost-effective, light-weight solar cell panels.
According to Dr. Robert Dalgliesh, one of the researchers of the project, the work makes us understand the potential of the joint use of neutron and X-ray scattering sources such as ISIS and Diamond in solving modern challenges for society. Using such sources help in making a stronger internal structure for the solar cell. By studying the layers in the solar cell that is responsible in converting sunlight into electricity, the different processing steps that change the overall efficiency and affect the overall polymer solar cell performance is also known.
Since most of the energy consumed today is through non-renewable sources, the demand for something that generates energy through a renewable source like the Sun is needed for the coming years. Since no highly efficient system that is capable of converting sunlight into electricity has been found until now, the cling-film solar cell will clearly pave way for the new age of renewable energy
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BiCMOS Technology

The need for high-performance, low-power, and low-cost systems for network transport and wireless communications is driving silicon technology toward higher speed, higher integration, and more functionality. Further more, this integration of RF and analog mixed-signal circuits into high-performance digital signal-processing (DSP) systems must be done with minimum cost overhead to be commercially viable. While some analog and RF designs have been attempted in mainstream digital-only complimentary metal-oxide semiconductor (CMOS) technologies, almost all designs that require stringent RF performance use bipolar or semiconductor technology. Silicon integrated circuit (IC) products that, at present, require modern bipolar or BiCMOS silicon technology in wired application space include the essential optical network (SONET) and synchronous digital hierarchy (SDH) operating at 10 Gb/s and higher. The viability of a mixed digital/analog. RF chip depends on the cost of making the silicon with the required elements; in practice, it must approximate the cost of the CMOS wafer, Cycle times for processing the wafer should not significantly exceed cycle times for a digital CMOS wafer. Yields of the SOC chip must be similar to those of a multi-chip implementation. Much of this article will examine process techniques that achieve the objectives of low cost, rapid cycle time, and solid yield