What were the prisoners doing?

a. They were trying to escape.

b. They were smashing the shop-windows.

c. They were fighting.

Why couldn’t the cars move?

a. It was too dark in the streets.

b. The traffic signals were not working.

c. It was a heavy traffic jam.

Why did the trouble begin?

a. The trouble began because the hydroelectric generator at Niagara broke down.

b. The trouble began because the city was flooded with water.

c. The trouble began because the power station was damaged in the earthquake.

Exercise 3. Read and translate the following expressions:

Power

Power engineering deals with the generation, transmission and distribution of electricity as well as the design of a range of related devices. These include transformers, electric generators, electric motors, high voltage engineering and power electronics. In many regions of the world, governments maintain an electrical network called a power grid that connects a variety of generators together with users of their energy. Users purchase electrical energy from the grid, avoiding the costly exercise of having to generate their own. Power engineers may work on the design and maintenance of the power grid as well as the power systems that connect to it. Such systems are called "on-grid" power systems and may supply the grid with additional power, draw power from the grid or do both. Power engineers may also work on systems that do not connect to the grid, called "off-grid" power systems, which in some cases are preferable to on-grid systems. The future includes Satellite controlled power systems, with feedback in real time to prevent power surges and prevent blackouts.

Questions:

1. What does power engineering deal with?
2. Who maintains an electrical network?
3. What is the function of the power grid?
4. Why do users purchase energy from the grid?
5. Where may power engineers work?
6. Why do "off-grid" power systems exist?
7. Why does the future include Satellite controlled power systems?

Exercise 5. Read the following text and make up 6 questions to it and answer them in English:

Control

Control engineering focuses on the modeling of a diverse range of dynamic systems and the design of controllers that will cause these systems to behave in the desired manner. To implement such controllers electrical engineers may use electrical circuits, digital signal processors, microcontrollers and PLCs (Programmable Logic Controllers). Control engineering has a wide range of applications from the flight and propulsion systems of commercial airliners to the cruise control present in many modern automobiles. It also plays an important role in industrial automation.

Control engineers often utilize feedback when designing control systems. For example, in an automobile with cruise control the vehicle's speed is continuously monitored and fed back to the system which adjusts the motor's power output accordingly. Where there is regular feedback, control theory can be used to determine how the system responds to such feedback.

Exercise 6. Look through the following table and fill in the missing parts of the text given below:

 

	Source	Advantages	Disadvantages
Petroleum (Oil)	Petroleum is a fossil fuel formed by heat and pressure from the Earth’s crust acting on the fossilised remains of dead animals and plants. Petroleum reserves exist in the Earth’s crust sandwiched between layers of impermeable rocks and porous rocks. The petroleum is extracted from these reservoirs drilling oil wells and sinking pipes into the reservoirs to pump the petroleum out.		§ Products of combustion (the gases given off when burnt) are atmospheric pollutants and greenhouse gases. § Accidents during transport, extraction and refining cause major environmental pollution.
Natural Gas	2.	§ Relatively easy to extract. § Requires little processing (is extracted in a ready to use form) § Is the cleanest of the fossil fuels.	3.
Coal	Coal is a fossil fuel. Coal is formed from the fossilized remains of plants that once grew on the earth. The action of the pressure and heat of the Earths crust over millions of years converts the fossilised remains of these plants into coal. Coal is mined from coal seams in the Earth’s crust. Where the coal is near the surface of the Earth, open cast mining is used but in areas where the seam is deep underground mining is used to extract the coal.	4.	§ Open cast mining damages the landscape and ecosystems. The burning of coal produces gases that are atmospheric pollutant and greenhouse gases. Due to the large amount of greenhouse gases coal produces power station require expensive pollution control measures.
Nuclear	5.	6.	§ Although small amounts of waste are produced, the waste is very dangerous. § The waste needs to be disposed of carefully and responsibly. § The risk of a nuclear accident can have catastrophic consequences as was the case of Chernobyl
Solar	This is energy from sunlight. Sunlight can be captured by solar panels and its energy transferred to electricity. Energy from the sun can also be focussed onto pipes carrying water transferring heat energy.	§ Free unlimited source of energy § No waste or greenhouse gases produced	7.
Wind	Wind is created by the action of warm air rising and cold air blowing to fill the void created. Hence, the source is the sun as it is its energy that warms the air.	8.	§ Unpredictable source of energy. § Wind farms can be unsightly and cause noise pollution.
Tidal	The pulling effect of the moon on the earth causes the oceans and seas to rise and fall. The movement of the rise and fall of the oceans and seas can be used to drive turbines.	§ A free source of energy. § No waste or greenhouse gases produced. § Tides are predictable.	§ Tidal barrages can affect the natural habitat of wildlife and impact the environment. § Can only supply energy when the tide is moving in or out.
Hydro	9.	§ Once the dam is built the energy is free. § No waste or greenhouse gases produced. § Very reliable source of energy	§ Dams are very expensive to build. § Dams cause flooding which seriously impact the environment and local habitats.
Waves	Waves are produced by the action of the wind on the seas and oceans.	§ A free source of energy. § No waste or greenhouse gases produced.	§ Dependant on the strength of the waves. § Needs to be capable of withstanding rough weather. § Sites are limited to only areas where the waves are consistently strong.
Geothermal	Heat from under the earth in volcanic regions is used to heat water to produce steam for running turbines for generating electricity. In some cases it is used to heat water for heating.	§ No fuel needed § Does no contribute to greenhouse gases	10.
Biomass	11.	12.	Produces greenhouse gases.

 

Parts of the text from the table:

A. – It is free. No waste or greenhouse gases produced.

B. – Produces greenhouse gases and atmospheric pollutants when burnt.

C. – Source not available at night. Can be an unreliable source of energy unless in a country with a hot climate.

D. – Limited sites available. Hazardous gases can be released from underground sites which require safe disposal.

E. – Easily converted to energy. Relatively easy to extract. Can be easily transported (pipelines, super-tankers)

F. – Water stored in a large volume in a reservoir behind a dam. The potential energy of the water can be transferred to kinetic energy in the turbines.

G. – The most common form of this fuel is Uranium. Uranium is a common metal found in rocks all over the world. However, the particular form of Uranium best suited as a nuclear fuel is Uranium – 235 and this is very rare. Uranium – 235 is extracted via mining and then processed to make it usable as a fuel.

H. – Is a renewable source as long as plant and trees are replaced. Cheap and easily available source of fuel.

I. – It is a fossil fuel. Its formation is similar to that for petroleum; however the conversion of the fossilized remains of the dead plants and animals to gas occurs at deeper depths in the Earths crust where the pressure and heat is greater. It is extracted in a similar way to petroleum by drilling holes and sinking pipes into the gas reservoirs, the gas travels to its surface under its own pressure

J. – Small amounts of fuel produce a large amount of energy. Does not produce atmospheric pollutants and greenhouse gases. Produces small amounts of waste.

K. – This is fuel obtained from decaying plant and animal material. Wood is one source as it can be burnt to provide heat energy. Sugar cane can be fermented to produce alcohol which can be used as a fuel.

L. – Of all the fossil fuels it has the largest reserves. It is relatively easy and inexpensive to extract.

 

Date: 2015-12-24; view: 1214