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ลำดับตอนที่ #8 : Sciman 4 - (30/10/59)

Class Work 4

(Section 427)

Group 7

-

Present to

Teacher Khin Saw Mon

Review Question

6. Describe the process that resulted in the formation of oil and natural gas.

          Organisms died and gather on the bottom of the ocean, lakes, lagoons or other aquatic environments poor in oxygen. After that, it will mixes with sediments (sand, clay, salt, etc.).

Then, it accumulates in successive layers over millions of years. These layers are push down by their own mass and the Plate Tectonics breaks and takes them deeper in the Earth’s crust. The deeper it subside, the more pressure and temperature increase.

Chemical reactions eliminate the nitrogen atoms and oxygen, leave only molecules formed from carbon and hydrogen which constitute the liquid and gaseous hydrocarbons. These hydrocarbons are to be found at the heart of the rock.

The hydrocarbons tend to close to the surface because it lighter than water. They will ooze out or will be bitumen, losing their volatile parts. But if the hydrocarbons meet seal or cap rock, they will be trapped underground.

In this part, the gaseous part of hydrocarbons rises above the oil, pushing water below and when many millions years pass, it will break out by geological forces or be found by human.

12. What environmental concern has caused people to be more accepting of nuclear power?

          Climate change had major implications for nuclear power. Since nuclear power don’t produce carbon dioxide, many people accept it.  Other is economic, oil and natural gas are more expensive, electricity from these two sources also costly so the nuclear power is more attractive.

20. What are the major environmental problems associated with the use of nuclear power?

            Biological Effects – Ionizing radiation can damage DNA or other important molecules in cells. The accumulated effects over many years may cause cancer.

Nuclear Waste Disposal – There are only 2 ways, reprocessing or placing the waste in the secure location. These waste will have to be placed in long-term storage underground.

Safety – Nearly all nuclear power plants have operated without serious accident but still, there are 3 accidents which make people concern about nuclear power plants safety.

7. List three negative environmental impacts of using biomass to provide energy

          Habitat & biodiversity loss – Many demand of wood resulted in the destruction of forest and may lead to extinction of plants and animals.

            Air pollution – Burning wood release high amount of smoke and other, such as carbon dioxide, which can lead illness and death.

            Climate change – When forests were destroyed by the using of biomass, the way to decrease carbon dioxide in the atmosphere also destroyed and it will cause climate change.

8. What are negative environmental impacts of developing hydroelectric power?

            Flooding - The creation of dams can also create flooding of land, which means natural environment and the natural habitat of animals, and even people, may be destroyed.

Community relocation – Building dams used large space of land. Some caused the displacement of over a million people.

Agriculture - Making dams on rivers affect the amount, quality and temperature of water that flow in streams which has serious effects on agriculture and drinking water.

1. Describe the hydrologic cycle.

The cycling of water through the environment follows these simple patterns. Moisture in the atmosphere condenses into droplets that fall into the earth as rain or snow, supplying all living things with its life-sustaining properties. Water, flowing over the earth as surface water or through the soil as groundwater, returns to the oceans, where it evaporates back into the atmosphere to begin the cycle again.

5. What is biochemical oxygen demand? How is it related to water quality?

            Biochemical oxygen demand or BOD is the amount of oxygen required to decay a certain amount of organic matter. BOD can use for testing how much the water is polluted. The greater the BOD, the more difficult it is for aquatic animals to survive and the less desirable the water is for human use. The more organic pollution, the greater the BOD.

9. What is thermal pollution? How can it be controlled?

            Thermal pollution occurs when an industry removes water from a source, uses the water for cooling purposes, and returns the heated water to its source.

            It can be controlled by use another ways to release cooling water. One is to construct a large shallow pound. Hot water is pumped into one end and cooler water is removed from the other end. The heat will release from the pound into the atmosphere. Second, cooling tower. The heated water is sprayed into the air and cooled by evaporation. Disadvantage of these first two ways is that large amount of water are lost by evaporation. Third, the dry tower. The heated will be pumped through tubes and the heat is release into the air. It’s the most expensive way to construct and operate.

Fourth presentation