Category Its Use and the Environment

Conversions and Equivalencies

(Conversions and Equivalencies also available in Table 3.4) Energy Units

1 Btu = 1055 J = 778 ft-lb = 252 cal 1 ft-lb = 1.356 J = 0.33 cal 1 calorie = 4.186 J 1 food calorie = 1000 cal = 1 kcal

1 ton of oil equivalent (toe) = 40 million Btu (MBtu) = 42 GJ 1 hp-hr = 2.68 X 10[30] J = 0.746 kWh 1 kWh = 3.61 X 10[31] [32] J = 3413 Btu = 2.65 X 106 ft-lb 1 quad = 1015 Btu 1 GJ = 10[33] J = 948,000 Btu

Power Units

1 watt = 1 J/s = 3.413 Btu/h 100 kWh/y = 11.4 W

1 hp = 550 ft-lb/s = 2545 Btu/h = 746 watts

1000 bbl/day of oil = 2.117 X 1012 Btu/yr 1 million bbl/day of oil (1 MBPD)

= 5.8 X 1012 Btu/day = 80 million tons per year of coal = _ ton per year of uranium oxide

Fuel Requirements for a 1000-MWe Power Plant (2.4 X 1011 Btu/day input)

Coal: 9000 tons/day or 1 unit train load (100 90-ton cars...

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Cold Fusion

In 1989, the scientific community was startled by the announcement of what some thought to be one of the major breakthroughs of the century: the possible achievement of the fusion of deuterium at room temperatures. Two chemists from the University of Utah had carried out an experiment that could be done in a test tube with equipment costing only thousands of dollars and with much simpler technology than that used in the types of fusion programs we have been describing.

The apparatus (Fig. 16.10) consisted of an ordinary test tube that contained a plati­num wire wrapped around a palladium metal rod. Both metals were immersed in heavy water—water enriched with deuterium...

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Cooking Stoves in Developing Countries

Household energy demands, especially those for cooking and heating, dominate the energy needs for developing countries. The majority of the population of developing countries live in rural settings, where cooking uses about 80% of basic energy demand. India has 75% of its population living in 570,000 villages. Rural energy demand there is met primarily by wood (60%) and dung and crop residues (30%). It has been esti­mated that 56% of the world’s population eats food cooked with such fuels. Women in many villages spend two hours per day gathering firewood for cooking purposes, and this takes time away from other household tasks such as getting water (Fig. 17.14). Less water often means increased health problems, whereas less wood means less hot water.

Подпись: EXAMPLE 17.2 If natural gas costs $1.00 per therm, what should be the price per cord of mixed hardwoods to deliver the same Btu? SOLUTION Using Table 17.5, we see that natural gas costs 13.33 X $1.00 = $13.33/MBtu. This should equal 0.083 X $/cord. Solving this finds the price per cord should be $161.

Firewood supplies are becomin...

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Effects and Uses of Radiation

A. Introduction

B. Radiation Dose

C. Biological Effects of Radiation

D. Background Radiation, Including Radon

E. Radiation Standards

F. Medical and Industrial Uses of Radiation Focus on 15.1 Food Irradiation

G. Radiation Protection

H. Summary

Special Topic: Radiation Detection Instruments

Effects and Uses of RadiationHOW WOULD YOU CHOOSE?

America’s Radiation Experiments

In the years since the demise of the Cold War and the fall of communism, a good deal of information has surfaced on U. S. experiments with ionizing radia­tion from the 1940s to the 1970s. Some examples:

• Unknowing or ill-informed people were subjected to radiation from direct exposure during A-bomb tests in Nevada or from injection of radioisotopes.

• Some of the above-ground nuclear tests in the 1940s were viewed by people (civilian and military...

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Home Heating Analysis Worksheet

Introduction

This home energy audit will guide you in calculating the heat loss of your residence. This audit includes heat gains from various sources; Item H (on the summary page) will allow you to compare the energy use of your home with that of others. You will also be able to compare costs of heating your home with various fuels by using Section II and Item F. Analysis of your findings will indicate which features in your house are wasting the greatest amounts of energy.

An easy-to-print PDF version of this worksheet is available for download on the companion Web site for this book.

Directions

Подпись: Page 1 A. B. C. D. Page 2 A. B. Fill in each of the blanks in Section I.

From your utility companies, find out the local cost per unit measure for each of the fuel sources in Section II.

Calculate the cost per MBtu delivered to...

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Summary and Outlook for Fusion

Fusion is the combining of two small nuclei to form a larger nucleus, with the release of energy. The reaction most commonly studied is D + T —— 4He + n + 17.6 MeV. For a fusion reactor to produce a net energy output, the D—T plasma must achieve the Lawson criterion—defined as the product of the particle density times the confinement time of the plasma—of about 1014 seconds per cubic cm. It must also reach a high plasma temperature (about 100 million °C). Confinement of the plasma is achieved with magnetic bottles of doughnut shape (Tokamaks) or with inertial confinement, as done in laser-induced fusion...

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Tapping the Earth’s Heat: Geothermal Energy

A. Introduction

B. Origin and Nature of Geothermal Energy

C. Hydrothermal Systems

D. Geothermal Exploration and Resources

E. Low-Temperature Geothermal Resources

F. Environmental Impacts

G. Summary

Tapping the Earth’s Heat: Geothermal EnergyHOW WOULD YOU CHOOSE?

A Hot Investment

A group of investors are interested in building a geothermal power plant. Pro­ponents have argued that the low cost of such plants—including incentives available through the government because this is a renewable resource—and its low environmental impact make geothermal a strong investment. They are looking into two fast-growing metropolitan areas—Atlanta and Phoenix. How would you choose in this matter?

A. Introduction

Geothermal energy is produced from heat originating in the earth’s interior...

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Radiation Dose

Ionizing radiation comes from gamma rays, X-rays, and charged particles such as elec­trons and alpha particles. Table 13.1 in Chapter 13 listed the properties of these ra­diations, including their abilities to penetrate matter. Gamma rays and X-rays are not charged, so they cannot ionize an atom directly through electrical interactions. How­ever, they produce electrons indirectly through other interactions with matter.

To understand the effects of radiation on human tissue, we must have some way of measuring the amount delivered. For many years after the discovery of X-rays, there was no adequate way to measure the amount received. Early X-ray workers noticed that hair fell out or that their skin became ulcerated in areas exposed to X-rays...

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