NUCLEAR ENERGY: Juan and Clifford

NUCLEAR ENERGY

BY: CLIFFORD AND JUAN

1) About Nuclear Energy:

- Nuclear energy is one of the cleanest source of energy that produces energy efficiently. It is very conservative form of energy as the same amount of Uranium-235 produces 10 million times more energy than the same amount of coal burnt. However, maintaining a nuclear power plant is very troublesome and dangerous as there are mountains of radioactive wastes as well as getting near the plant is very radioactive.

ßß Example of a Nuclear Power Plant

2) Pros and Cons of Nuclear Energy (Blue = pros, Red = cons):

- It produces almost no greenhouse gases, reducing global warming problems.

- It is a very reliable energy source, because very little reactants to produce energy is needed everytime, hence there are almost never shortage of supply.

- By far, nuclear power plant produces the most energy out of the rest of the energy power plant. Nuclear power plant produces phenomenal amounts of energy despite its little requirements to produce.

- Although nuclear power plants do not emit greenhouse gases, they produce radioactive wastes, which are harmful to the environment and they are very difficult to remove.

- Nuclear power plants are very difficult to manage and very dangerous. These power plant expose workers to excessive radiation, which harms their lives. Even during the mining of Uranium-235, exposure to radioactivity is possible.

- Nuclear power plants are prone to massive disasters. An example of this is the chernobyl incident that happened in the Ukraine in 26th of April 1986.

ßß Cross section of a nuclear power plant.

ßß Aftermath of the Chernobyl Disaster.

3) How is the nuclear energy formed?

- A nuclear power plant produces its energy from Uranium-235. Energy is produced through a process called nuclear fission. In nuclear fission, neutrons collides with the Uranium-235 atoms, creating an unstable atom. These atoms then split, producing huge amounts of energy while splitting. However, after the split, neutrons are released by the atoms, creating more neutrons to collide with another Uranium-235 atoms, creating a chain reaction. The energy produced is calculated by a famous Einstein equation, E= mc² where E= energy, m= mass, and c = speed of light (3x10⁸ m/s). That is a humongous amount of energy.

- This amount of energy is released by rods of Uranium-235, into the water and the water turned into steam. These steams then turn the turbines to produce energy.

- Other methods of producing energy (nuclear energy) is possible. Examples of it are nuclear fusion and etc.

http://www.youtube.com/watch?v=N7C14UIKuv8 à This is a video explaining the nuclear fission in detail.

ßß Illustration of a nuclear fission.

4) The uses of nuclear energy

- Food and Agriculture
The use of isotopes and radiation techniques in agriculture come under this category. Leading organizations have been working on the technology to increase agricultural production, improve food availability and quality, reduce production costs and minimize pollution of food crop.

- Human Health
One very common application of nuclear energy is in the treatment of cancer - radiotherapy. Radiotherapy can also be used to cure cancers like breast cancer, lung cancer, etc. Also, small amounts of radioisotope tracers are used for diagnostic and research purposes. These techniques have helped in monitoring the levels of toxic substances in food, air and water. This is one of the benefits of using nuclear energy.

5) Reasons to use nuclear energy

Reduces the Dependence on Fossil Fuels
There has been an increase in production and supply of fossil fuels like oil and gas, as the world has been using them at an tremendous pace. Their deposits are emptying. On the other hand, nuclear energy requires very little quantity of fuel to produce large quantities of energy. Consider this; one ton of uranium can produce energy that is more than that of several million tons of coal and oil.

Clean Water
The water discharged from nuclear power plants is very safe, free of any radiation or harmful pollutants, and meets all regulatory standards. Hence, helps in protecting the aquatic life and conserving wildlife. Some energy creates a pollution called water pollution and nuclear energy does not pollute the water and polluting the water can harm the aquatic lives.

REFERENCE:

http://www.buzzle.com/articles/nuclear-energy-pros-and-cons.html

http://www.buzzle.com/articles/how-does-a-nuclear-power-plant-work.html

http://www.brainpop.com/technology/energytechnology/nuclearenergy/preview.weml (Video about nuclear power plants)

Biofuel by Nicholas and Zachary

Biofuel by Nicholas and Zachary 4CH3

What is biodiesel?

Biodiesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics.

Is Biodiesel the same thing as raw vegetable oil?No!

Fuel-grade biodiesel must be produced to strict industry specifications in order to insure proper performance. Biodiesel is the only alternative fuel to have fully completed the health effects testing requirements of the 1990 Clean Air Act Amendments. Biodiesel that meets the specifications and is legally registered with the Environmental Protection Agency is a legal motor fuel for sale and distribution. Raw vegetable oil cannot meet biodiesel fuel specifications, it is not registered with the EPA, and it is not a legal motor fuel.
Biodiesel is defined as mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats which conform to specifications for use in diesel engines. Biodiesel refers to the pure fuel before blending with diesel fuel. Biodiesel blends are denoted as, "BXX" with "XX" representing the percentage of biodiesel contained in the blend (ie: B20 is 20% biodiesel, 80% petroleum diesel).

Why should I use biodiesel?

Biodiesel is better for the environment because it is made from renewable resources and has lower emission compared to petroleum diesel. It is less toxic than table salt and biodegrades as fast as sugar. This makes it a better alternative compared to diesel.

What is Biogas?
Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Biogas originates from biogenic material and is a type of biofuel. Biogas is produced by anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material and energy crops. This type of biogas consists of methane and carbon dioxide. Another type of gas generated by the use of biomass is wood gas, which is created by gasification of wood or other biomass. This type of gas consists primarily of nitrogen, hydrogen, and carbon monoxide, with trace amounts of methane.

Solid biofuels
Examples include wood, sawdust, grass cuttings, domestic refuse, charcoal, agricultural waste, non-food energy crops and dried manure.
When raw biomass is already in a suitable form (such as firewood), it can burn directly in a stove or furnace to provide heat or raise steam. When raw biomass is in an inconvenient form (such as sawdust, wood chips, grass, urban waste wood, agricultural residues), the typical process is to densify the biomass. This process includes grinding the raw biomass to an appropriate particulate size, which depending on the densification type can be from 1 to 3 cm (1 in), which is then concentrated into a fuel product. The current types of processes are wood pellet, cube, or puck. The pellet process is most common in Europe and is typically a pure wood product. The other types of densification are larger in size compared to a pellet and are compatible with a broad range of input feedstocks. The resulting densified fuel is easier to transport and feed into thermal generation systems such as boilers.
A problem with the combustion of raw biomass is that it emits considerable amounts of pollutants such as particulates and PAHs (polycyclic aromatic hydrocarbons). Even modern pellet boilers generate much more pollutants than oil or natural gas boilers. Pellets made from agricultural residues are usually worse than wood pellets, producing much larger emissions ofdioxins and chlorophenols.

So in conclusion… Use Biofuels instead of fossil fuels! Do YOUR part to save the Earth! :D

Thai Ming and Jun Xian - Green technology

Green Technology

Definition: Green Technology is technology that is designed to be safe for the environment and used in a way that doesn't consume natural resources.


There are 5 types of green technology:

1)Energy - Green technology that produces energy without consuming natural resources or harming the environment. (a.k.a Renewable sources of energy e.g. Hydroelectric)

2)Building - Designing and building houses in a way that utilises materials and tools efficiently to reduce resource consumption.

3)Preferred Purchasing - Buying and producing products that have little effect on the environment.

4)Chemistry - Using chemical products that reduce environmental damage.

5)Nanotechnology - Implementing green principles to the field of nanotechnology.

Green Energy - Green energy utilises the natural power of the earth's environment to create energy. This may include hydroelectric power stations built on waterfalls, geothermal power stations near volcanos and wind turbines around normally windy areas. With the exception of geothermal energy, green power stations directly harness the kinetic energy of the earth's environment (i.e. running water, moving wind) and uses it to create electricity by spinning a turbine. Green energy also includes methods of using energy efficiently, such as using a fan instead of air-conditioning or switching off any unnecessary lights during the day.

Green Building - Green building involves building structures in a green way, as well as designing it so that it maximises energy efficiency. This includes using materials that are quickly renewable such as bamboo (fastest growing plant in the world), building in a location that has windy areas to save on heating/air-conditioning, designing the building in a way to maintain temperature as well as providing the structure with a system to reduce water consumption.

Green Preferred Purchasing - Green preferred purchasing involves the consumer choosing green products over conventional products, such as rechargable batteries. This also extends to the producer researching methods to produce goods in a green way or producing goods that are environmentally friendly.

Green Chemistry - Green chemistry involves the creation of chemical products in a green way, and expands to the whole process of producing the desired chemical. It involves reducing any toxic waste produced, reducing pollution, using non-toxic components, creating environmentally-friendly products and reducing energy consumed in the process of making the chemical.

Green Nanotechnology - Green nanotechnology combines principles of green chemistry and green building to create nanomaterials and products that have no toxic materials, require less energy to make, and are renewable wherever possible. Green nanotechnology also involves using nanotechnology to further augment the efficiency of already existing green methods. For example, in green chemistry, the use of nanoscale membranes may help filter out unwanted products and reduce and waste.

References:
http://www.epa.gov/gcc/
http://en.wikipedia.org/wiki/Green_building
http://en.wikipedia.org/wiki/Green_nanotechnology
http://www.green-technology.org/what.htm
http://hubpages.com/hub/Green-Technology