Sunday, May 26

Uranium Nuclear Fuel


Introduction to Uranium nuclear fuel:

The basic fuel materials for the generation of nuclear power are the elements Uranium and Thorium. Of these, Uranium has played a major rule. Uranium is by no means a rare substance and it has been estimated to be around 4ppm of the earth’s crust. In fact, Uranium is more abundant  than relatively familiar elements such us silver, mercury, bismuth and cadmium. Although the estimated total weight of Uranium in the earth’s crust is 1014 metric tons yet most deposits are of such a low grade that the extraction of the metal would appear to be uneconomical. Uranium is extracted from the ores containing primary minerals Pitchblende and Uraninite (UO2  and  U3O8). Uranium is solvent extracted to finally produce ‘yellow cake’ containing 75% to 85% of  U3O8.  This is subjected to further treatment leading to almost pure Hexafluoride (UF6) as a product.  Uranium dioxide (UO2), Uranium metal, Uranium carbide and Uranium nitride are some of the final products that will be used as reactor fuel.Please express your views of this topic Definition of Torque by commenting on blog.

Uranium metal fuel:


Metallic Uranium was used as a fuel in most of the earlier nuclear reactors, largely because it provides the maximum number of Uranium atoms per unit volume. Since it has poor mechanical properties and great susceptibility to radiation damage, Uranium metal fuel  is not used in power reactors in many countries. It was used as a fuel in the older gas-cooled reactors.


Uranium dioxide nuclear fuel:


Uranium dioxide (UO2) , a ceramic which is the most common fuel material in commercial power reactors, has the advantages of high-temperature, stability and adequate resistance to radiation. It also has a high melting point of 2865oC and is chemically inert to attack by hot water. It is this property which makes it attractive for use in water- cooled reactors, where the consequences of a cladding failure could be catastrophic if the fuel material reacted readily with the water at the existing high temperature. Another beneficial property of Uranium dioxide is its ability to retain a large proportion of the fission gases provided the temperature does not exceed about 1000oC. The major disadvantage of Uranium dioxide as a fuel material is its low thermal conductivity, although this is partially offset by the fact that very high temperatures are permissible in the centre of the fuel element.

Solar Wind Geothermal


Introduction to solar, wind and geothermal energy:

Renewable energy comes from natural resources like sunlight, tides, wind, rain and geothermal heat. Three major renewable energy resources are wind power, solar energy and geothermal energy. Advantage of renewable energy is that they are inexhaustible, environmentally friendly with low dangerous pollutant emissions.



Solar energy


Solar energy is derived from the sun in the form of solar radiation. Electrical generation by solar power relies on heat engines and photovoltaic. Solar applications include day lighting, solar architecture, solar cooking, solar hot water and for industrial purposes.

Solar technologies can be classified as passive or active, depending on the method of intake, conversion and distribution of solar energy. Active solar techniques include solar thermal collectors and photovoltaic panels to harness the energy. Passive solar techniques include selecting materials, orienting to the Sun, light dispersing properties, and designing spaces that naturally circulate air.


Advantages and disadvantages of wind energy


Flow of air is used to run wind turbines which provide a source of clean and renewable energy for homes or business. Small wind energy devices generate power very cost effectively.

Wind turbines range from 600 kW to 5 MW of power. The power output is the cube of the wind speed, hence power output increases as the wind speed increases. Offshore and high altitude areas where winds are stronger are preferred for wind farms.

Advantages:

Wind energy is friendly to the surrounding environment,

Wind turbines take up less space than a power station.

The wind is free.

Wind turbines can generate energy in remote locations.

Disadvantages:

The winds unreliability factor, which can be too low to support a wind turbine or wind farm,

Wind turbines produce less electricity than fossil- fueled power station; hence multiple wind turbines are needed to make an impact.

Construction can be very expensive.

The noise pollution from commercial wind turbines is sometimes similar to a small jet engine.


Geothermal power energy


The earth contains a large amount of energy in the form of heat. Geothermal energy is obtained by using the earth's heat from kilometers deep into the Earth's crust or from some meters. All this geothermal energy has the potential to generate power to provide electricity.

Three different types of geothermal energy power plants are used to generate power: flash, dry steam and binary.

The best advantage of geothermal energy is that they are useful even in cold regions like Norway and Sweden by using ground source heat pumps.

Experience Weightlessness


Introduction to experiencing weightlessness

As we know that the earth attracts every another body towards its centre. The force with which the earth attracts another bodies is called the weight. The weight of the body on the earth is equal to the product of the mass of the body and the acceleration due to gravity of earth. Here we can say that the weight = mass × acceleration due to gravity = mg. The value of acceleration due to gravity (g) is not constant throughout the earth. The weight of the body changes as the value of the acceleration due to gravity changes. Here we discuss in which situation the weight of the body becomes zero that means the condition of the body is weightlessness.I like to share this Units for Acceleration with you all through my article.


Experiencing weightlessness and conditions related to it


The weight mg of the body is also known as the true weight or the static weight of the body. We become conscious for our weight, only when weight is opposed by some other object. Actually, the secret of measuring the weight of the body with the weighing machine lies in fact that as we place the body on the weighing machine, the weighing machine opposes the weight of the body. The reaction of the weighing machine gives the weight of the body. There are four main conditions in which the body becomes weightlessness. The four conditions are as follow:

(i) When the body falling freely under the gravity the weight of the body is zero. For example, a lift is falling freely; any ball falling from the tower etc. experiences the weightlessness.

(ii) When the satellite revolves in the orbit around the earth experiences weightlessness. The gravitational force acting towards the centre of the earth balances by the centripetal force acting on the body so that the weight is zero.

(iii) When the bodies are at null point in the outer space. After the certain height, the gravitational pull of the earth becomes less and it is more for moon so that the body will feel the attraction force towards the moon. At that particular height where the gravity of the earth balances by the gravity of moon, the body experiences weightlessness.

(iv) When we reach at the center of the earth, we feel weightlessness. As the value of the acceleration due to gravity at the centre of the earth is zero and so, the weight of the body at the centre of the earth is also zero.


Conclusion of experiencing weightlessness


Weightlessness causes very serious problems to the astronauts. It becomes quite difficult for them to control their movements. Everything in the artificial satellite has to be kept tied down. To overcome this problem we create the artificial gravity so that they do not feel the weightlessness.

Friday, May 24

What Is Synchronous Motor


Introduction to what is synchronous motor

A synchronous motor (electric) is the another name of alternating current motor which converts the electrical energy into some mechanical energy. In the working of the  synchronous motor the rotor is spinning with the coils and then develops the magnetic field which is used to rotates the motor. Synchronous motor’s speed is determined by  pair numbers of the magnetic poles and the number of oscillations of the electric current (a.c) which is the alternating source of electricity.


Description of Synchronous Motor


The availability of the synchronous motors are in the sub fractional and self excited sizes to very high power and operating on the direct current also. The two types of the synchronous motors, which are used generally: one is non excited synchronous motor and the other is direct current excited synchronous motor. The non excited synchronous motors are constructed on the basis of the idea of reluctance and hysteresis designs, and they starts by the are self circuits and they do not require no any excitation supply of the energy. The reluctance design motors have 30 horse power efficiency. In the synchoronous motors there is a need of low torque and we can use these in the instrumentation applications. Synchronous motors are having the toothed rotors in some designs. The main parts of the synchronous motor are:

(i) the startor is the outer part as a shell of the motor which carries the armature windings, this winding is distributed for poly phase alternating current. The armature creates the rotating magnetic field.

(ii) the rotor is the moving part of the synchronous motor. The permanent magnet is produced by the field due to the windings.

(iii) the function of the slip rings in rotor is to supply the direct current to the windings of the wires in the direct current excited type synchronous motors.


Uses of synchronous Motor


Almost the synchronous motors of low horse power are used to provide the constant speed. The synchronous motors of high horse power are used for converting the energy  alternating current in the work which is useful for the different purposes in the heavy industries and the important use is that it work on power factor having value unity, that means the power loss is negligible.

Energy From The Sun Is Called


Introduction on energy from the sun is called:

The energy from sun is called Solar Energy. In fact, the best form of energy available to us is “SOLAR ENERGY”. The sun is the source of all energy. The sun provides us heat and light energy free of cost. The energy obtained from the sun is called solar energy. The nuclear fusion reactions taking place inside the sun keep on liberating enormous amounts of heat and light energy. This heat and light energy is radiated by the sun in all directions in the form of solar energy. The sun has been radiating an enormous amount of energy at the present rate for nearly 5 billions years and will continue radiating energy at that rate for nearly 5 billion years more. Since, the sin is very far away only a small fraction of the solar energy radiated by the sun reaches the outer layer of the earth’s atmosphere. A little less than half of the atmosphere actually reaches the surface of earth. The rest of solar energy is reflected back into space by the atmosphere and also absorbed by the atmosphere as it comes down through it towards the surface of the earth.


Advantages of solar energy


The best form of energy,solar energy which reaches the earth is absorbed by land and water-bodies as well as by plants. The solar energy trapped by land and water-bodies causes many phenomena in nature like winds, storms, rain, snowfall and sea-waves. The plants utilize solar energy to prepare food by the process of photosynthesis. The various sources of energy derive their energy from the sun, the best source of energy.

1. Non-renewable sources of energy, fossil fuels also derive their energy from sun. It is solar energy, which is converted into petroleum and oil.

2. Solar energy does not cause any pollution as compared to non-renewable sources of energy.

3. The solar energy is best form of energy because it is available in a diffused form so it is available to almost everyone on the earth.


Conclusion to solar energy


Finally ,the best source of energy, that is , solar energy is clean. It is a clean alternative to fossil fuels and nuclear power and it will never run out. It’s silent. Solar power can be captured anywhere without creating noise pollution that might otherwise up set neighbours and wildlife. It works wherever the sun shines. It doesn’t matter how remote, solar can generate energy where no other form of power can be obtained. Thus, no danger of damaging our already damaged environment further and you can be part of the Green initiative, lower your carbon footprint, and save our planet from harmful greenhouse gases.

Regular and Diffuse Reflection


Introduction to Regular and Diffused Reflection

When light traveling in one medium strikes a boundary leading to another medium, a part of incident light is through back into the original medium one. This phenomenon is called reflection of light.

Reflection is of two types:

Regular reflection
Irregular reflection or diffuse reflection


Description to regular and diffuse reflection


1.    Regular reflection: When the reflection surface is smooth and well polished, the parallel rays falling on it are reflected parallel to another one, the reflected light goes in one particular direction. This is regular reflection. The smooth and well polished surface is called mirror. Silver metal is one of the best reflectors of light. So, ordinary mirrors are made by depositing a thin layer of silver metal on one side of a plane glass sheet. The silver layer is protected by a coat of red paint. The reflection of light in a mirror takes place at the silver surface. A plane mirror is represented by a straight line, with a number of short, oblique lines showing back of the mirror.

2.    Diffuse reflection: When the reflecting surface is rough, the parallel rays falling on it are reflected in different direction. Such a reflection is known as diffuse reflection or irregular reflection or even scattering of light. In this, a surface will behave as a smooth surface as long as the surfaces variations are small as compared to the wavelength of incident light. As wavelength of visible light is very small therefore, every surface acts as a rough surface and scattering of light or irregular reflection is more common. For example, any object in a room can be seen from all the parts of the room. This is because surface of the object is rough and it scatters or reflects light in all directions.



Regular and Diffused Reflection : Summary


Reflection of light is the phenomenon of bouncing back of light in the same medium on striking the surface of any object.

Different Ways to Conserve Energy


Introduction to different ways of conserving energy:

When energy is saved, the demand for fossil fuels as oil, coal and natural gas is reduced. Less use of fossil fuels means less pollution, lower emissions of carbon dioxide and less global warming.Below is a house that uses various renewable energy and acts as an example for various ways to conserve energy.


Ways of conserving energy


Plant large, shady trees and paint a dark color to a house in a cold climate or a light color to a house in a warm climate. Trees absorb carbon dioxide from the air and give out oxygen.

Do not leave house hold appliances like Air Conditioner, computer, television, radio etc. on while you are out or when not needed.

Do not cool or warm areas that people are not in and close doors and windows in unused rooms.

Replace light bulbs with energy saving fluorescent bulbs.

Air dishes and clothes whenever possible.

Set lower temperature for the thermostat in the water heater, refrigerator and other heating or cooling devices to reduce electricity consumption. This cuts off the current supply sooner than; this is more efficient than using very hot water and then mixing it with cold water before for use.


Use solar water heaters.

Clean air filters regularly in the air conditioners. Free passage of air doesn't stress the device and thus reduce current.

Insulate doors, roofs and windows to reduce leakage of hot or cool air.

Use dishwasher and clothes washer at full capacity to as multiple usage increases electricity consumption.

Whenever possible get a walk, use mass transit or car pool than using your car daily. This reduces fuel consumption.

Use energy efficient appliances- with energy star label; though expensive, they use less current and reduce pollution and over a period of time save money.

Recycle and reuse whenever possible. Avoid packaged products and go for recyclable ones as they reduce pollution.

ways of conserving energy


Conclusion to different ways to conserve energy


From the discussion on conserving energy, we conclude that besides conserving energy, think of ways to use alternative sources of energy like, solar power, wind power, human powered mechanical energy etc.