CHAPTER 13:
ENERGY
Objectives
1. Note the proportions of all energy resources on Earth in terms of commercial and natural energy sources. Distinguish
between renewable and nonrenewable commercial energy sources.
2. Describe crude oil formation, and list the common petroleum products. Analyze the global distribution of conventional
crude oil, oil sand, and oil shale reserves. Discuss the advantages and disadvantages of fossil fuel use.
3. Define natural gas. Describe the uses and occurrences of natural gas. List the advantages and disadvantages of using
natural gas as an energy source. Discuss coal, its formation, distribution and uses. List advantages and disadvantages of
using coal as a fuel source.
4. Briefly describe the components of a conventional nuclear reactor. List the advantages and disadvantages of using
conventional nuclear fission to create electricity. Be sure to consider the whole nuclear fuel cycle, including disposal of
radioactive wastes, safety and decommissioning of nuclear power plants, and the potential for proliferation of nuclear
weapons.
5. Briefly outline why the mid-twentieth century vision of nuclear power has not lived up to expectations. Distinguish
between light-water and breeder reactors. Note research progress on nuclear fusion.
6. Define energy efficiency. Outline the technological progress of energy efficiency. Define life cycle cost and
cogeneration, and describe their potential for saving energy.
7. List all common forms of renewable energy resources. Distinguish active from passive solar energy. Discuss emerging
solar technology, its advantages and disadvantages.
8. Define hydropower and its global role in energy supply. Discuss the advantages and disadvantages of high dam
hydropower energy. Note minor forms of hydropower.
9. Discuss the status of wind power, liquid biofuels, and biomass energy resources as a part of global commercial energy
resources. Discuss the status of geothermal energy and hydrogen fuel cells. Distinguish among dry steam, wet steam, and
hot water sources of geothermal energy. Note the four potential problems associated with widespread hydrogen fuel use.
10. Explain the three general conclusions about making the transition to sustainable energy societies.
Key Terms {(Terms are listed in the same font style as they appear in the text.)}
active solar heating system
(p. 305)
advanced light-water reactors
(ALWRs) (p. 296)
age of wind energy (p. 311)
animal manure (p. 312)
biodiesel (p. 312/314)
bioenergy (p. 312)
biofuels (p. 312)
biomass (p. 312)
bio-refineries (p.315)
bitumen (p. 285)
breeder nuclear fission reactors (p.
297)
cellulosic ethanol (p. 313)
Chernobyl (p. 293)
coal bed methane (p. 286)
coal gasification (p. 289)
coal liquefaction (p. 289)
coal-burning power plant
(p. 298)
cogeneration (p.299)
combined heat and power (CHP) (p.
299)
commercial energy (p. 280)
containment vessel (p. 291)
control rods (p. 290)
conventional (light) oil (p. 283)
conventional natural gas (p. 286)
coolant (p. 290)
corporate average fuel economy
(CAFÉ) standards (p. 299)
Energy
crop residues (p. 312)
crude oil (p. 283)
decommissioned (p. 296)
dry casks (p. 291)
dry steam (p. 315)
earth tubes (p. 306)
energy conservation (p. 298)
energy efficiency (p. 298)
ethanol (p. 312)
Exporting Countries (OPEC)
(p. 284)
flexible fuel cars (p. 313)
fuel cell(p. 301)
fuelwood crisis (p. 312)
geothermal energy (p. 315)
geothermal heat pumps (p. 315)
green architecture (p.302)
green industrial revolution
(p. 308)
green roofs (p. 302)
high-level radioactive waste
(p. 295)
high-temperature, gas-cooled
reactors (p. 296)
hybrid cars (p. 300)
hydrogen (p. 316)
hydropower (p. 309)
hydrothermal reservoirs (p. 315)
incandescent light bulb (p. 298)
internal combustion engine
(p. 298)
kerogen (p. 294)
light-water reactors (LWRs)
(p. 290)
liquefied natural gas (LNG)
(p. 287)
liquefied petroleum gas (LPG)
(p. 286)
living roofs (p. 302)
macropower (p. 318)
methane hydrate (p. 287)
micro-hydro generators (p. 309)
micropower (p.318)
natural gas (p. 286)
net energy (p. 282)
net energy ratio (p. 282)
nonrenewable energy resources
(p. 280)
nuclear fuel cycle (p. 282)
nuclear fusion (p. 297)
nuclear power plant (p. 298)
oil sand (p. 285)
oil shales (p. 285)
Organization of Petroleum
passive solar heating system
(p. 305)
peak production (p. 283)
petrochemicals (p.283)
petroleum (p. 283)
photovoltaic (PV) cells
(p. 307)
plug-in hybrid electric vehicle
(p. 300)
refinery (p. 283)
103
renewable energy resources (p. 280)
reserves (p. 283)
seasonal energy efficiency ratings(p.
306)
shale oil (p. 294)
solar cells (p. 307)
solar cookers (p. 307)
solar thermal plants (p. 306)
strawbale houses (p. 302)
superefficient and ultralight cars (p.
300)
superinsulated house (p. 302)
switchgrass (p. 313)
synfuels (p. 289)
synthetic natural gas (SNG) (p.
289)
tar sand (p. 285)
unconventional natural gas (p.
286)
water-filled pools (p. 291)
wet steam (p. 315)
wind, hydropower, and biomass
(p. 280)
Outline
13-1 Major Energy Sources:
A. Ninety-nine % of the energy that heats the Earth and all of our buildings comes directly from the sun.
1. The sun provides other indirect forms of renewable solar energy such as wind, falling/flowing water, and biomass.
2. Commercial energy sold in the marketplace makes up the remaining 1 % of the energy we use, most from
nonrenewable resources.
B. About 82 % of commercial energy consumed in the world comes from nonrenewable energy sources (76 % from fossil
fuels, and 6 % from nuclear energy).
C. The remaining 18 % of commercial energy used comes from renewable energy resources such as biomass,
hydropower, wind, geothermal, and solar energy. About 50 % of people in developing countries use biomass energy in
the form of fuelwood and charcoal.
D. Fossil fuels are widely used because they are abundant, easily transportable, \and inexpensive compared to most other
alternatives.
13-2 Fossil Fuels:
A. Crude oil is a thick, gooey liquid consisting of hundreds of combustible hydrocarbons mixed with small amounts of
sulfur, oxygen, and nitrogen impurities. Some of the products of crude oil distillation, called petrochemicals, are used
as raw materials in organic chemicals, pesticides, plastics, synthetic fibers, paints, medicines, etc. Three geological
events led to the presence of oil:
1. Sediments buried organic material faster than it could decay.
2. Seafloors with these sediments were subjected to the right pressure and heat to convert organic material to oil.
3. Oil collected in porous limestone or sandstone and was capped by shale or silt, which kept it from escaping.
B. Eleven OPEC countries have 78 % of the world’s proven oil reserves.
1. Saudi Arabia has the largest supply of oil reserves with 25 %, followed by Canada at 15 %. The OPEC nations are
almost all in the Middle East. It is thought that their production of global oil will increase from 30 % at present to
50 % in the future.
2. Oil revenues for OPEC countries tripled from 199 billion in 2002, to 600 billion in 2006.
C. The U.S. produces about 9 % of the world’s oil, but uses 25 % of it.
1. In 2003, the U.S. imported about 55 % of the oil it used. By 2020, the U.S. could be importing 64–70 % of the oil
it will use.
2. Some analysts feel that importing oil is not all bad, that U.S. oil reserves should be held in reserve.
D. Known and projected global reserves should last for 42–93 years and U.S. reserves for 10–48 years depending on how
rapidly we use oil. Use of conventional oil at current rates means we need to discover oil reserves equal to a new Saudi
Arabian supply every 10 years.
1. Oil production is expected to peak sometime between 2010 and 2030.
2. Oil will become increasingly more expensive.
E. Oil sand or tar sand is a mixture of clay, sand, water, and organic material called bitumen—thick, sticky, heavy oil
with high sulfur content. Northeastern Alberta, Canada, has about three-fourths of the world’s oil sand reserves; about
one-tenth are close enough to be recovered.
1. The extraction and processing of this material uses a great deal of energy, so it reduces net energy yield for the oil.
2. Use of these oil sands could reduce U.S. dependence on imports from the Middle East.
3. This extraction process has severe environmental impacts on land and produces more water pollution, air
pollution, and more CO2/unit energy than conventional crude oil.
4. Oil shale deposits may be another potential source of oil. The material in this shale is kerogen. It is estimated that
there are 240 times more global supplies than for conventional oil. At present it costs more to produce than the
fuel is worth.
F. Natural gas consists mostly of methane, with small amounts of heavier hydrocarbons and a small amount of hydrogen
sulfide. Propane and butane gases are liquefied from a natural gas field and removed as liquefied petroleum gas (LPG)
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that is stored in pressurized tanks. Methane is dried of water, cleaned, and pumped into pressurized pipelines for
distribution.
G. Natural gas is a versatile fuel. It can be used to run fleet vehicles, medium-sized turbines to produce electricity. They
are cheaper to build, require less time to install, and are easier and cheaper to maintain than coal and nuclear power
plants. Russia and Iran have about 50 % of the world’s reserves of conventional natural gas and global reserves to last
62–125 years.
H. Natural gas was burned to provide about 53 % of the heat in U.S. homes and 16 % of the country’s electricity.
I. Coal is a solid fossil fuel formed 300–400 million years ago. It is mostly carbon with small amounts of sulfur and trace
amounts of mercury. Coal mining is ecologically destructive. Coal is burned to produce electricity and steel. 62 % of
the world’s electricity is produced by burning coal, which is the most abundant fossil fuel.
J. Reserves in the U.S., Russia, and China could last hundreds to thousands of years .The U.S. has 27 % of the world’s
proven coal reserves. Russia has 16 % and China has 12 %. But coal has severe environmental impact on land, air, and
water.
K. Coal can be converted to synthetic natural gas (SNG) by coal gasification or to liquid fuel by coal liquefaction.
1. These procedures require 50 % more coal be mined and will add 50 % more CO2 emissions to the atmosphere.
2. These techniques are not possible without huge government subsidies.
3. A consortium of major oil companies are working on ways to reduce CO 2 emissions during the coal gasification
process; this would be a cheaper, cleaner way to produce electricity.
13-3 Nuclear Energy
A. In a conventional nuclear reactor, isotopes of uranium and plutonium undergo controlled nuclear fission, and the
resulting heat is used to produce steam that spins turbines to generate electricity.
1. A controlled chain reaction occurs when nuclei of atoms are split. The heat from the reactions is used to produce
high-pressure steam that spins turbines that generate electricity.
2. Light-water reactors (LWRs) produce about 85 % of the world’s nuclear-generated electricity.
3. Long, thin rods are packed with fuel pellets, and each pellet contains energy equivalent to one ton of coal or four
barrels of crude oil.
4. The control rods regulate the rate of fission and amount of power the reactor produces.
5. A moderator (material that slows down neutrons) keeps the reaction going. It may be water, graphite, or
deuterium.
6. A coolant, usually water, circulates through the core to remove heat to keep the components from melting and to
produce steam for generating electricity.
7. A containment vessel with thick, strong walls surrounds the reactor as a safety backup. Walls are usually made of
four-foot reinforced concrete with a steel liner.
8. Spent rods are stored on-site in water-filled pools or dry casks with thick steel walls. These rods must be stored
safely for 10,000–20,000 years until radioactivity levels are safe.
9. All the safety features make nuclear power plants very expensive to build and maintain.
B. The nuclear fuel cycle includes mining uranium, processing it to make a satisfactory fuel, using it in the reactor, safely
storing highly radioactive wastes, and dealing with the reactor after its useful life.
1. A nuclear power plant must be decommissioned after 15–60 years of operation. It contains large quantities of
radioactivity that must be kept out of the environment.
C. Nuclear power has not lived up to its promise.
1. The goals set forth in the fifties have not been met even with an investment of two trillion dollars worldwide.
2. Electricity production from nuclear power plants is the slowest growing energy source.
3. The U.S. has not ordered any new reactors since 1978; all 120 plants ordered since 1973 have been cancelled.
4. Several major reasons for the failure of nuclear power to grow are multibillion-dollar cost overruns, higher
operating costs, more malfunctions than expected, and poor management.
5. Public concerns about safety and stricter government regulations are two major setbacks.
6. Investors are concerned about the economic feasibility of nuclear power.
7. Vulnerability of these plants to terrorist attacks is another concern.
D. The advantages of conventional nuclear fuel are fairly low environmental impact and low risk of accident, but costs
are high, storing wastes is difficult and costly, and facilities are vulnerable to terrorist attack.
E. There is great concern about the vulnerability of U.S. nuclear power plants and the nuclear wastes they store to
terrorist attack.
1. The 2002 study by the Nuclear Control Institute found that the plants were not designed to withstand the crash of
a large jet.
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2.
Insufficient security at nuclear plants is another concern. The same study also found that many security guards at
nuclear power plants have low morale, are overworked, underpaid, undertrained, and not equipped to repel a
serious ground attack by terrorists.
3. Spent fuel rods stored outside of the containment shells at nuclear plants are vulnerable to attack.
F. Scientists cannot agree on whether there is a safe method to store high-level radioactive waste. (HLRW). However,
most agree that the safest and the cheapest way to store HLRW is in secured engineered structures.
G. There is disagreement over the decision to store high-level nuclear wastes at an underground storage site in Nevada, in
the U.S.
1. This facility is expected to cost 58 billion dollars to build and is scheduled to open in 2010.
2. After it is filled, the facilities will be monitored for 300 years, and then sealed.
3. The Yucca Mountain site is located in an area that currently receives only 15 centimeters of rain per year.
4. There is concern that rock fractures and tiny cracks may allow water to leak into the site and corrode the
containers, releasing radioactive material. This material could explode.
5. The Yucca Mountain site has a nearby active volcano and 32 active earthquake faults running through the site.
6. In January 2002 the U.S. energy secretary stated that the site was scientifically sound despite the concerns of
scientists.
7. Shipment of radioactive materials across the country makes them open to terrorist attack.
8. The U.S. National Academy of Sciences, in 2002, urged the U.S. government to slow down and rethink the
nuclear waste storage process.
9. Nevada is still fighting the project in the courts.
H. A nuclear power plant must be decommissioned when it reaches the end of its useful life.
1. Scientists have proposed three ways to decommission plants:
a. Dismantle the plant and store its large volume of radioactive materials in a high-level waste storage facility.
b. Put up a physical barrier around the plant and set up full-time security for 30–100 years before the plant is
dismantled.
c. Enclose the entire plant in a tomb that must last and be monitored for thousands of years.
I. Nuclear power is an expensive way to produce electricity, even with government subsidies.
J. Nuclear breeder reactors have been very costly with bad safety records, and the technology has essentially been
abandoned.
1. Breeder nuclear fission reactors generate more nuclear fuel than they consume. This means that the world’s
known uranium reserves would last at least 1,000 years.
K. Nuclear fusion has a number of advantages, but after 50 years this technology is still at a laboratory stage.
L. There is disagreement over whether the U.S. should phase out nuclear power or keep it an option.
1. Some analysts feel that nuclear power should be phased out regarding all or most government subsidies, and the
money should be used to subsidize and accelerate the development of other promising energy technologies.
2. According to investors and the World Bank analysts, conventional nuclear power simply can’t compete in today’s
energy market.
3. Proponents of nuclear power feel that governments should continue funding research and development. They say
that we need to keep nuclear options open if various renewable energy options fail to keep up with electricity
demands and fail to reduce CO2 emissions to suitable levels.
13-4 Energy Efficiency as an Energy Source
A. Energy efficiency is a measure of the useful energy produced compared to the energy that is converted to low-quality
heat energy.
1. About 84 % of all commercial energy used in the U.S. is wasted. About 41 % is wasted because of the degradation
of energy quality imposed by the second law of thermodynamics.
2. About 43 % of the energy used is unnecessarily wasted by such things as motor vehicles, furnaces, and people
living and working in leaky, poorly designed buildings.
3. Four energy devices commonly used waste large amounts of energy: the incandescent light bulb (95 % waste), a
nuclear power plant (86–92 % waste), an internal combustion engine (75–80 % waste), and a coal-burning power
plant (66 % waste).
B. Net energy efficiency is a measure of the useful energy we get from a resource after subtracting the energy used and
wasted to make energy available.
C. Some industries save energy and money by using cogeneration, a combination of heat and power systems. The same
fuel source may produce both steam and electricity. About 9 % of U.S. electricity is produced by cogeneration.
D. The best way to save energy in transportation is to increase the fuel efficiency of motor vehicles.
1. Between 1973 and 1985 fuel efficiency rose sharply for new cars sold in the U.S. This occurred because of
government-mandated standards.
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2.
3.
Between 1985 and 2004 the average fuel efficiency for new cars sold in the U.S. leveled off or declined slightly.
Fuel efficient cars are available but account for less than 1 % of all cars sold in the U.S. because the inflationadjusted price of gasoline in the U.S. is still fairly low. If all the true cost factors were included in the price of
gasoline, it will be selling at $11 per gallon.
4. More than half the vehicles in the U.S. are low-efficiency pickups, minivans, and SUVs compared to only 5 % in
1990.
E. Gasoline-electric hybrid vehicles have a battery and a small internal combustion engine to recharge the battery. Current
models can get as much as 50 mpg. The fuel-efficiency of all cars can double if car bodies were made of ultralight and
ultra-strong composite materials.
F. Fuel-cell vehicles burn hydrogen fuel. The hydrogen fuel combines with oxygen in the air to produce electrical energy
for power and to produce water vapor. Twenty years from now, China plans to become the largest producer and seller
of fuel cell vehicles globally.
1. Fuel cells are at least twice as efficient as internal combustion engines.
2. They have no moving parts and require little maintenance.
3. They produce little or no pollution.
G. Commercial and residential buildings in the U.S. waste 65 % of U.S. Electricity and emit 30 % of the greenhouse
gases. Correct orientation of a building can save 20 % of the heating costs when the building is well insulated—green
architecture.
H. We can save energy in existing buildings by insulating them, plugging leaks, and by using energy-efficient heating and
cooling systems, appliances, and lighting.
1. Insulate and plug leaks since about one-third of heated air escapes through closed windows, holes, and cracks.
2. Use energy-efficient windows with low-E (low-emissivity) to cut heat losses by two-thirds and reduce CO2
emissions.
3. Stop other heating and cooling losses by wrapping ducts in attics and basements.
4. Heat water more efficiently by use of a tankless instant water heater fired by natural gas of LPG—NOT
electricity. These last three to four times longer and cost less to operate than conventional tank heaters.
5. Use energy-efficient appliances such as energy-efficient lighting; electricity cost can be cut by 30–60 emissivity
by using fluorescent bulbs. The Department of Energy (DOE) has set federal energy-efficiency standards for more
than 20 appliances. Similar programs exist in 43 other countries. Environmental benefits are conservatively
estimated at 60–80 billion dollars.
I. A glut of low-cost fossil fuels is part of the reason for energy wastage. The price does not include the harmful costs.
Also, there are very few large and long-lasting tax breaks, and other economic incentives for consumers and
businesses to invest in improving energy efficiency.
13-5 Renewable Energy Resources
A. One of the principles of sustainability is to rely mostly on renewable energy. We can use solar energy directly, or
indirectly, through flowing water, wind, and biomass. Geothermal energy is also another renewable source of energy.
B. However, renewable energy only provides 18 % of the global energy supplies, mainly because of inequitable subsidies
and inaccurate pricing. But recent studies show that by 2025, 20 % of global electricity will be from renewable energy,
which will increase to 50 % by 2050.
C. We can heat buildings actively by pumping a liquid (active solar heating) through rooftop collectors; or it can be done
passively by orienting energy efficient windows toward the sun.
D. Active solar collectors now provide hot water for more than 40 million households—59 million of them in China.
E. Conventional air conditioning uses fossil fuels and uses up a lot of electricity. To cool houses naturally, superinsulate
them and work with nature. Open windows for breezes; use fans to move air; block sunlight with deciduous trees,
window overhangs, or awnings; use a light-colored roof; and hang reflecting foil in the attic.
F. Solar thermal systems can collect and transform radiant energy to high-temperature thermal energy (heat), which can
be used directly or converted to electricity.
G. Solar cells can be used to produce electricity directly.
1. Photovoltaic (PV) cells/solar cells convert solar energy directly into electrical energy. The solar cell is a
transparent wafer that is energized by sunlight, causing electrons in the semiconductor to flow and creating an
electrical current.
2. Banks of solar cells or arrays of solar cells can be used to generate electricity.
3. Less-developed countries, such as India, are installing solar-cell systems in thousands of villages. China plans to
use solar cells and wind turbines to provide electricity to 29,000 villages to ease its dependence on coal.
4. Solar cells currently supply about 0.05 % of the world’s electricity, but by 2040 they could supply 16 % of the
world’s supply.
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H. Flowing water trapped behind dams and released as needed can spin turbines and produce 25 % of the global
electricity.
1. Hydropower is an indirect form of renewable solar energy.
2. Three methods are used to produce such electricity.
a. Large-scale hydropower uses a high dam across a large river to create a reservoir. The advantages and
disadvantages of this method are given in figure 18-22.
b. Small-scale hydropower uses a low dam with little or no reservoir across a small stream with the turbines
turned by the stream’s flow. A micro-generator, a small turbine, can even be used to provide electricity for a
single home.
c. Pumped-storage hydropower uses surplus electricity from a conventional power plant to pump water from a
lower reservoir to a reservoir at a higher elevation for release through a turbine when more electricity is
needed.
1. There is pressure on the World Bank to stop funding large-scale dams because of environmental and social
consequences. Small-scale projects eliminate most of the harmful environmental effects of large-scale projects.
2. The use of micro-hydro generation may become an increasingly important way to produce electricity, where
floating turbines use the power of a river’s flow to turn a rotor with blades that feed generators to produce electric
current.
3. Electricity can also be produced by tapping into energy from tides and waves. The costs are high, however, and
there are few favorable locations for this technology.
I. Wind power is the world’s most rapidly growing form of indirect solar energy. This indirect form of solar energy can
be captured by wind turbines and converted into electrical energy. Since 1990 wind power has been the fastest
growing source of energy. Within a few years, wind is expected to be the cheapest way to produce electricity. Analysts
expect increasing use of offshore wind farms because wind speeds over water are often stronger.
J. Plant materials and animal materials can be burned to provide heat or electricity, or can be converted into gaseous or
liquid biofuels.
1. Most biomass is burned directly for heating and cooking.
2. This comprises up to 95 % of the energy used in the poorest developing countries, and 10 % global energy.
3. Biomass plantations plant and harvest large amounts of fast-growing trees, shrubs, perennial grasses, and water
hyacinths to produce biomass fuel.
4. Crop residues and animal manure can be converted to biofuels.
5. Ecologists argue that it makes more sense to use animal manure as a fertilizer and crop residues to feed livestock,
retard soil erosion, and fertilize the soil.
K. Liquid biofuels such as ethanol and biodiesel produced from plants and plant wastes can help replace gasoline and
diesel fuel, and dominate the rapidly growing bioenergy industry.
L. Geothermal energy is heat stored in the Earth’s interior. Scientists estimate that using just 1 % of the available
geothermal heat can provide 250 times more energy that all the petroleum reserves. Presently geothermal electricity is
1 % of global supplies.
M. When hydrogen gas burns in air, or in fuel cells, it combines with oxygen to produce nonpolluting water vapor.
Hydrogen used as a fuel can produce more energy per gram than any other fuel. There are four problems with
widespread use of hydrogen as fuel:
1. Hydrogen is chemically locked up in water and organic compounds.
2. It takes energy and money to produce hydrogen from water and organic compounds. It is not a source of energy, it
is a fuel produced by using energy.
3. Current versions of fuel cells are expensive but are the best way to use hydrogen to produce electricity.
4. Whether hydrogen-based energy system produces less air pollution (CO2) than fossil fuel system depends on how
the hydrogen is produced.
13-6 Sustainable Energy Transition
A. Energy experts who have evaluated energy alternatives have come to three general conclusions.
1. There will be a gradual shift from large, centralized macropower systems to smaller micropower systems such as
wind turbines, fuel cells for cars, household solar panels, etc.
2. The best alternatives combine improved energy efficiency and the use of a mixture of sustainably produced
biofuels to make the transition to a diverse mix of locally available, renewable energy resources over the next
several decades.
3. Fossil fuels will continue to be used in large quantities because of their low price and accessibility. The challenge
is to find ways to reduce the harmful effects of fossil fuels use.
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