تدریس

wo mediums reach the same temperature.
Heat can be transferred in three different modes: conduction, convection, and radiation.
All modes of heat transfer require the existence of a temperature difference, and all modes
are from the high-temperature medium to a lower-temperature one.
Conduction Heat Transfer
Conduction is the transfer of energy from the more energetic particles of substance to the
adjacent less energetic ones as a result of interactions between the particles. Conduction
can take place in solids, liquids, or gases. In gases and liquids, conduction is due to the
collisions and diffusion of the molecules during their random motion. In solids, it is due
to the combination of vibrations of the molecules in a lattice and the energy transport by
free electrons. A cold canned drink in a warm room, for example, eventually warms up to
the room temperature as a result of heat transfer from the room to the drink through the
aluminum can by conduction.
The rate of heat conduction through a medium depends on the geometry of the medium,
its thickness, and the material of the medium, as well as the temperature difference across the
medium. We know that wrapping a hot water tank with glass wool (an insulating material)
reduces the rate of heat loss from the tank. The thicker the insulation, the smaller the heat
loss. We also know that a hot water tank loses heat at a higher rate when the temperature
of the room housing the tank is lowered. Further, the larger the tank, the larger the surface
area and thus the rate of heat loss.
Consider steady heat conduction thro

eir everyday usage (steady job, uniform distribution, etc.).
The total energy content of a control volume during steady-flow process remains constant
(ECV = constant). That is, the change in the total energy of the control volume during such a
process is zero (DECV = 0). Thus the amount of energy entering a control volume in all forms
(heat, work, mass transfer) for a steady-flow process must be equal to the amount of energy
leaving it. In rate form, it is expressed as  =in outE E .
The amount of mass flowing through a cross section of a flow device per unit time
is called the mass flow rate, and is denoted by m. A fluid may flow in and out of a control
volume through pipes or ducts. The mass flow rate of a fluid flowing in a pipe or duct is pro-
portional to the cross-sectional area Ac of the pipe or duct, the density r, and the velocity V
of the fluid. The flow of a fluid through a pipe or duct can often be approximated to be
one dimensional. That is, the properties can be assumed to vary in one direction only (the
direction of flow). As a result, all properties are assumed to be uniform at any cross section
normal to the flow direction, and the properties are assumed to have bulk average values
over the entire cross section. Under the one-dimensional flow approximation, the mass
flow rate of a fluid flowing

odynamics is simply an expression of the conservation of energy
principle, and it asserts that energy is a thermodynamic property. The second law of ther-
modynamics asserts that energy has quality as well as quantity, and actual processes occur
in the direction of decreasing quality of energy. For example, a cup of hot coffee left on a
table eventually cools, but a cup of cool coffee in the same room never gets hot by itself. The
high-temperature energy of the coffee is degraded (transformed into a less useful form at a
lower temperature) once it is transferred to the surrounding air.
Heat and Other Forms of Energy
Energy can exist in numerous forms such as thermal, mechanical, kinetic, potential, electri-
cal, magnetic, chemical, and nuclear, and their sum constitutes the total energy E (or e on
a unit mass basis) of a system. The forms of energy related to the molecular structure of a
system and the degree of the molecular activity are referred to as the microscopic energy.
The sum of all microscopic forms of energy is called the internal energy of a system, and is
denoted by U (or u on a unit mass basis).
The international unit of energy is joule (J) or kilojoule (1 kJ = 1000 J). In the English
system, the unit of energy is the British thermal unit (Btu),which is defined as the energy
needed to raise the temperature of 1 lbm of water at 60 by 1°F. The magnitudes of kJ and
Btu are almost identical (1 Btu = 1.055056 kJ). Another well-known unit of energy is the
calorie (1 cal = 4.1868 J), which is defined as the energy needed to raise the temperature of
1 g of water at 14.5 by 1°C.
Internal energy may be v

in power plants and industrial heating applications:
Distillate oils: These are higher-quality oils that are highly refined. They contain
much less sulfur compared to residual oils. A typical composition of distillate oils is
87.2 percent carbon, 12.5 percent hydrogen, and 0.3 percent sulfur. The higher heating
value for this composition is 45,200 kJ/kg.
Residual oils: These oils undergo less refining. They are thicker with higher molecular
mass, higher level of impurities, and higher sulfur content. A typical composition is
85.6 percent carbon, 9.7 percent hydrogen, 2.3 percent sulfur, 1.2 percent nitrogen,
0.8 percent oxygen, 0.1 percent ash, and 0.3 percent moisture. The higher heating value
for this composition is 42,500 kJ/kg.
Natural Gas
Natural gas is mostly methane (CH4) where its percentage varies between 60 and 98 percent.
It also contains small amounts of ethane, propane, butane, nitrogen, oxygen, helium, CO2,
and other gases. It exists as a gas under atmospheric conditions and is stored as a gas under
high pressure (15 to 25 MPa). It is mostly transported in gas phase by pipelines in and
between cities and countries. When pipeline transportation is not feasible, it is first lique-
fied to about −160°C using advanced refrigeration technologies before being carried in
large insulated tanks in marine ships. Natural gas is used in boilers for space heating, hot
water and steam generation, industrial furnaces, power plants for electricity production,
and internal combustion engines.
The higher and lower heating values of methane are 55,530 kJ/kg and 50,050 kJ/kg,
respectively. The heating value of natural gas depends mainly on the fraction of methane.
The higher is the methane fraction, the higher is the heating value. Natural gas is commonly
approximated as methane without much sacrifice in a

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C H A P T E R 1
Introduction to
Renewable Energy
1-1 WHY RENEWABLE ENERGY?
To meet its energy needs, the world community currently depends heavily on fossil fuels
that are nonrenewable and unfriendly to the environment. Table 1-1 presents total world
delivered energy consumption based on end-use sector and fuel type. Breakdown of each
fuel by sector and each sector by fuel is also provided. As shown in Fig. 1-1, more than half
of the global energy is used by the industrial sector (54.6%), followed by the transportation
sector with 25.6 percent, the residential sector with 12.7 percent, and the commercial sector
with 7.1 percent (EIA, 2018). Energy use is expected to increase worldwide, driven mainly
by industry, but this will mostly take place in developing countries with strong economic
growth.
Total global energy supply in 2017 was 589 Quad Btu, which is equivalent to 5.6 × 1017 kJ.
Fossil fuels accounted for 82.7 percent (27.1% coal, 33.4% oil, 22.2% natural gas) of this
total energy production. Renewable energy (including hydroelectric power), which is envi-
ronment-friendly and can be harvested indefinitely, was responsible for 12.7 percent of the
total energy supply globally. Nuclear power supplied the remaining 4.6 percent of the total
energy supply (Fig. 1-2) (EIA, 2018).
In 2015, total electricity generation in the world was 24,255 TWh (or 24.255 × 1012 kWh
since 1 TWh = 1 billion kWh = 109 kWh). Fossil fuels accounted for 66.3 percent of total
electricity generation in the world with 39.3 percent for coal, 22.9 percent for natural gas,
and 4.1 percent for oil. Renewable energy (including hydroelectric power) and nuclear
power were responsible for 23.1 percent and 10.6 percent of global electricity generation,
respectively (Fig. 1-3). A total of 5603 TWh (or 5.603 × 1012 kWh) of renewable electricity
was generated that year (IEA, 2017).
Total installed capacity of electricity in the United States in 2016 was 1074 GW, and
the U.S. power plants generated 4077 TWh (4.077 × 1012 kWh) of electricity that year.
Figure 1-4 shows the percentages of electricity generation in the United States by the fuel
type and source. Approximately 83.9 percent of electricity was generated by coal, natural
gas, and nuclear power plants. The remaining 16.1 percent was generated mostly by renew-
able sources including hydro (6.5%) and wind (5.5%). The remaining generation was due to
biomass, solar, and geothermal (EIA, 2018).
A comparison of U.S. electricity production data to global electricity generation data
shows that the share of renewable electricity in the United States is considerably less than
that in the world. Therefore, great potential exists to increase the share of renewables in 2 Chapter 1. Introduction to Renewable Energy
TABLE 1-1 Total World Delivered Energy Consumption by End-Use Sector and Fuel in 2017 (EIA, 2018)
All values are in Quad Btu (quadrillion Btu). (1 quadrillion Btu = 1 × 1015 Btu = 0.95 × 1015 kJ)
Fuel Total Electricity Residential Commercial Industrial Transportation
All End-Use
Sectors
Oil* 196.7 6.7 8.5 3.9 69.7 106.7 188.8
Natural gas 130.7 44.0 20.6 8.8 53.2 4.1 86.6
Coal 159.8 90.5 4.3 1.6 63.5 0.0 69.4
Nuclear 26.9 26.9 — — — — —
Electricity — — 21.0 16.8 35.1 1.6 74.5†
Renewables 74.9 55.5 1.3 0.2 17.9 — 19.4
Total 589.0 223.6† 55.7 31.3 239.4 112.4 438.8
*The values given for oil also include other nonpetroleum liquid fuels such as ethanol, biodiesel, coal-to-liquids,
natural gas liquids, and liquid hydrogen.
†The difference between the total energy value of fuel consumption to produce electricity (223.6 Quad Btu) and the
actual amount of electricity consumed by all end-use sectors (74.5 Quad Btu) is equal to the energy lost during the
production of electricity, which is equal to 223.6 - 74.5 = 149.1 Quad Btu. As a result, the difference between the totals
in the second and last column is also equal to 589.0 - 438.8 = 150.2 Quad Btu, which is very close to 149.1 Quad Btu.
Transportation,
25.6%
Residential,
12.7%
Commercial,
7.1%
Industrial,
54.6%
Figure 1-1 Percentages of global
energy use by end-use sectors in
2017 (EIA, 2018).
Nuclear,
4.6%
Coal,
27.1%
Natural gas,
22.2%
Oil,
33.4%
Renewables,
12.7%
Figure 1-2 Percentages of total world
primary energy supply by fuel in 2017
(EIA, 2018). 1-1 Why Renewable Energy? 3
the U.S. energy mixture. In 2000, only nine percent of electricity came from renewables,
and EIA (2018) projections indicate that the renewables will constitute 18 percent of elec-
tricity generation by 2040. Coal- and nuclear-based electricity generations are expected to
decrease in the coming years, but natural gas electricity generation is expected to increase
due to additional shale gas reserves.
Renewable electricity generation by source in the United States is given in Fig. 1-5.
Total generation by renewables was about 640 billion kWh in 2017. This is projected to
increase above 1600 billion kWh by the year 2050. Renewable electricity generation in 2017
is dominated by hydropower and wind, but solar electricity increased at the highest rate
among all energy sources. Solar electricity is estimated to take the greatest share by the
year 2050, followed by wind, hydropower, and geothermal. Other renewables represented
in Fig. 1-5 are due mostly to biomass electricity production by the means of MSW/LFG
(municipal solid waste/land fill gas) (EIA, 2018).
Renewables are currently the fastest-growing energy source in the world. Depletion
and emission concerns over fossil fuel use and increasing government incentives can cause
even higher growth in the use of renewables in the coming decades. The fastest-growing
Oil,
4.1%
Renewable,
7.1%
Hydro,
16.0%
Nuclear,
10.6%
Natural gas,
22.9%
Coal,
39.3%
Figure 1-3 Percentages of global electricity generation by fuel type and source
in 2015. Total electricity generation = 24,255 TWh (IEA, 2017).
Hydro,
6.5%
Other,
2.6%
Biomass,
1.5%
Coal,
30.4%
Nuclear,
19.7%
Natural gas,
33.8%
Wind,
5.5%
Figure 1-4 Percentages of electricity generation by fuel type and source in the
United States in 2016 (EIA, 2018). 4 Chapter 1. Introduction to Renewable Energy
renewable sources are solar and wind. The installed wind capacity has increased from
18 GW in 2000 to 539 GW by the end of 2017. The solar power capacity has increased
by 97 GW in 2017 bringing the global capacity to over 400 GW. The installed capacity
of hydropower exceeds 1250 GW worldwide. Hydroelectric, geothermal, and wind power
generation technologies are able to compete with fossil fuel–based electricity generation
economically, but solar electricity generation is still expensive. However, steady decreases
in solar electricity cost combined with increased government incentives are likely to help
wider use of solar electricity in the coming years.
EXAMPLE 1-1 In Table 1-1, the total energy consumption by different energy sources is given to be 589.0 Quad Btu
while the total energy use by all end-use sectors is 438.8 Quad Btu. Explain the difference between
these two values. Using the data in Table 1-1, calculate the total amount of energy lost during the
production of electricity by all energy sources. Also, calculate the amount of electricity produced in
kWh and the overall thermal efficiency of electricity production by all energy sources.
SOLUTION The difference between the total energy value of fuel consumption to produce electricity
(223.6 Quad Btu, third column, last row) and the actual amount of electricity consumed by all end-use
sectors (74.5 Quad Btu, last column, fifth row) is equal to the energy lost during the production and
distribution of electricity, which is equal to
Energy lost = 223.6 − 74.5 = 149.1 Quad Btu
The difference between the totals in the second and last column is equal to
Energy lost = 589.0 − 438.8 = 150.2 Quad Btu
which is very close to the value of 149.1 Quad Btu.
The amount of electricity produced is expressed in kWh as
21.83 trillion kWh
Electricity produced (74.5 10 Btu) 1 kJ
0.94782 Btu
1 kWh
3600 kJ
21.83 10 kWh
15
12
= × 
 
 
 

= × =
An Analysis of World
Energy Consumption
1800
1600
1400
1200
1000
800
600
400
200
0
2017
History Projections
Solar PV
Wind
Geothermal
hydroelectric
other
2010 2020 2030 2040 2050
Figure 1-5 Renewable electricity
generation by source in the United
States, in billion kWh (EIA, 2018). 1-1 Why Renewable Energy? 5
The thermal efficiency of a power plant is defined as the power produced divided by the energy
consumed. According to the data in Table 1-1, 223.6 Quad Btu of energy is consumed in all power
plants worldwide, and 74.5 Quad Btu of electricity is produced. The overall thermal efficiency of
producing electricity is then
33.3%
Electricity produced
Energy consumed
74.5 10 Btu
223.6 10 Btu 0.333th,overall
15
15
η = = ×
× = =
That is, about 67 percent of energy is lost during the conversion of energy sources (coal, oil, natural
gas, renewable) into electricity. ▲
EXAMPLE 1-2 Ton of oil equivalent (toe) is an amount of energy unit commonly used to express large amounts of
energy. It represents the amount of energy released by burning 1 ton (1000 kg) of crude oil. One toe
is taken equal to 41.868 GJ, sometimes rounded to 42 GJ. The power plants in the United States gen-
erated 4.05 × 109 MWh of electricity in a year. According to the data in Table 1-1, 74.5 Quad Btu of
electricity is produced. Express these values in the toe unit. Also, determine the percentage of global
electricity generation that occurred in the United States.
SOLUTION Noting that 1 MWh = 1000 kWh, 1 kWh = 3600 kJ, 1 GJ = 1 × 106 kJ, and 1 toe = 41.868 GJ,
we express electricity generation in the United States in toe, as follows:
Electricity generation (in U.S.) (4.05 10 MWh) 1000 kWh
1 MWh
3600 kJ
1 kWh
1 GJ
1 10 kJ
1 toe
41.868 GJ
9
6
3.48 10 toe8
( )= × 
 
 ×

 
 
 

= ×
Noting that 1 Quad = 1 × 1015 Btu and 1 toe = 41.868 GJ, we express global electricity generation in
toe, as follows:
Electricity generation (world) (74.5 Quad) 1 10 Btu
1 Quad
1.055 kJ
1 Btu
1 GJ
1 10 kJ
1 toe
41.868 GJ
15
6
1.88 10 toe9
= ×
 
 
 
 ×

 
 
 

= ×
The percentage of global electricity generation that occurred in the United States is determined to be
18.5%Percent generation in U.S. Electricity generation (U.S.)
Electricity generation (world)
3.48 10 toe
1.88 10 toe 0.185
8
9= = ×
× = =
That is, 348 million toe of electricity is generated in the United States and 1.88 billion toe of electricity
is generated in the world. The U.S. electricity generation represents 18.5 percent of global generation.
Note that toe unit is not normally used to express the amount of electricity. Instead some multiples of
kWh such as MWh, GWh, and TWh are used. ▲
Consequences of Fossil Fuel Combustion
Fossil fuels have been powering industrial development and the amenities of modern life
since the 1700s, but this has not been without undesirable side effects. Pollutants emitted
during the combustion of fossil fuels are responsible for smog, acid rain, and numerous
other adverse effects on the environment. Environmental pollution has reached such high
levels that it has become a serious threat to vegetation, wildlife, and human health. Air pol-
lution has been the cause of numerous health problems including asthma and cancer. But
this fossil fuel–based economy is not sustainable since the estimated life of known reserves
is limited. Therefore, the switch to renewable energy sources is inevitable.
Ton of Oil Equivalent
(toe) Unit 6 Chapter 1. Introduction to Renewable Energy
Carbon dioxide (CO2) is the primary greenhouse gas that contributes to global
warming. Global climate change is widely regarded as due to the excessive use of fossil
fuels such as coal, petroleum products, and natural gas in electric power generation, trans-
portation, buildings, and manufacturing, and it has been a concern in recent decades. The
concentration of CO2 in the atmosphere as of 2019 is about 410 ppm (or 0.41%). This is
20 percent higher than the level a century ago. Various scientific reports indicate that the
earth has already warmed about 0.5°C during the last century, and it is estimated that the
earth’s temperature will rise another 2°C by the year 2100. A rise of this magnitude is feared
to cause severe changes in weather patterns with storms and heavy rains and flooding at
some parts and drought in others, major floods due to the melting of ice at the poles, loss
of wetlands and coastal areas due to rising sea levels, variations in water supply, changes in
the ecosystem due to the inability of some animal and plant species to adjust to the changes,
increases in epidemic diseases due to the warmer temperatures, and adverse side effects on
human health and socioeconomic conditions in some areas.
The combustion of fossil fuels produces the following undesirable emissions (Fig. 1-6):
• CO2, primary greenhouse gas: contributes to global warming
• Nitrogen oxides (NOx) and hydrocarbons (HC): cause smog
• Carbon monoxide (CO): toxic
• Sulfur dioxide (SO2): causes acid rain
• Particulate matter (PM): causes adverse health effects
Notice from this emissions list that CO2 is different from the other emissions in that
CO2 is a greenhouse gas and a natural product of fossil fuel combustion while other emis-
sions are harmful air pollutants.
The concern over the depletion of fossil fuels and pollutant and greenhouse emissions
associated with their combustion can be tackled by essentially two methods:
1. Using renewable energy sources such as solar, wind, hydroelectric, biomass, and
geothermal to replace fossil fuels.
2. Implementing energy efficiency practices in all aspects of energy production, dis-
tribution, and consumption so that less fuel is used while obtaining the same use-
ful output.
Energy efficiency is to reduce energy use to the minimum level, but to do so without
reducing the standard of living, production quality, and profitability. Energy efficiency is an
expression for the most effective use of energy resources, and it results in energy conserva-
tion. Energy efficiency can only reduce fossil fuel use while renewable energy can directly
replace it.
Figure 1-6 Effects of undesirable
emissions from the combustion
of fossil fuels.
FOSSIL FUEL EMISSIONS
CO2 ⇒ global warming
NOx and HC ⇒ smog
CO ⇒ toxic
SO2 ⇒ acid rain
PM ⇒ adverse health effects 1-1 Why Renewable Energy? 7
Renewable Energy Sources
The main renewable energy sources include solar, wind, hydro, biomass, and geothermal
(Fig. 1-7). Energy sources from the ocean, including ocean thermal energy conversion
(OTEC), wave, and tidal, are also renewable sources, but they are currently not economical
and the technologies are still in the experimental and developmental stage.
An energy source is called renewable if it can be renewed and sustained without any
depletion and any significant effect on the environment. It is also called an alternative,
sustainable, or green energy source (Fig. 1-8). Fossil fuels such as coal, oil, and natural gas,
on the other hand, are not renewable, and they are depleted by use. They also emit harmful
pollutants and greenhouse gases.
The best-known renewable source is solar energy. Although solar energy is sufficient
to meet the entire energy needs of the world, currently it is not used as extensively as fos-
sil fuels because of the low concentration of solar energy on earth and the relatively high
Figure 1-8 Renewable energies such as solar water collectors are called green energy since they emit
no pollutants or greenhouse gases.
Figure 1-7 The switch from fossil
fuels to renewable energy sources
is inevitable.
RENEWABLE ENERGY
SOURCES
Solar
Wind
Hydro
Geothermal
Biomass
Ocean (OTEC, wave, tidal) 8 Chapter 1. Introduction to Renewable Energy
capital cost of harnessing it. The conversion of kinetic energy of wind into electricity via
wind turbines represents wind energy, and it is one of the fastest-growing renewables as
wind turbines are being installed all over the world. The collection of river water in large
dams at some elevation and then directing the collected water into a hydraulic turbine is
the common method of converting water energy into electricity. Hydro or water energy
represents the greatest amount of renewable electricity production, an

shall be arrested or detained without being at once informed of the
charges against him or without the immediate privilege of counsel; nor shall he be
detained without adequate cause; and upon demand of any person such cause must
be immediately shown in open court in his presence and the presence of his counsel.
Article 35• Regulation of evidence collection
The right of all persons to be secure in their homes, papers and effects against
entries, searches and seizures shall not be impaired except upon warrant issued for
adequate cause and particularly describing the place to be searched and things to be
seized, or except as provided by Article 33.
Each search or seizure shall be made upon separate warrant issued by a competent
judicial officer.
Article 36• Prohibition of cruel treatment
• Prohibition of torture
The infliction of torture by any public officer and cruel punishments are absolutely
forbidden.
Article 37
In all criminal cases the accused shall enjoy the right to a speedy and public trial by an
impartial tribunal.
• Right to fair trial
• Right to public trial
• Right to speedy trial
He shall be permitted full opportunity to examine all witnesses, and he shall have the
right of compulsory process for obtaining witnesses on his behalf at public expense.
• Right to examine evidence/ witnesses
At all times the accused shall have the assistance of competent counsel who shall, if
the accused is unable to secure the same by his own efforts, be assigned to his use by
the State.
• Right to counsel
Article 38• Protection from self-incrimination
No person shall be compelled to testify against himself.
Confession made under compulsion, torture or threat, or after prolonged arrest or
detention shall not be admitted in evidence.
No person shall be convicted or punished in cases where the only proof against him is
his own confession. constituteproject.org PDF generated: 27 Jul 2018, 21:09
Page 9Japan 1946
Article 39• Prohibition of double jeopardy
• Protection from ex post facto laws
• Principle of no punishment without law
No person shall be held criminally liable for an act which was lawful at the time it was
committed, or of which he has been acquitted, nor shall he be placed in double
jeopardy.
Article 40• Protection from false imprisonment
Any person, in case he is acquitted after he has been arrested or detained, may sue
the State for redress as provided by law.
Chapter IV: The Diet
Article 41
The Diet shall be the highest organ of state power, and shall be the sole law-making
organ of the State.
Article 42• Structure of legislative chamber(s)
The Diet shall consist of two Houses, namely the House of Representatives and the
House of Councillors.
Article 43
Both Houses shall consist of elected members, representative of all the people.
The number of the members of each House shall be fixed by law.• Size of first chamber
• Size of second chamber
Article 44• Eligibility for first chamber
• Eligibility for second chamber
The qualifications of members of both Houses and their electors shall be fixed by
law. However, there shall be no discrimination because of race, creed, *******, social
status, family origin, education, property or income.
Article 45• Term length for first chamber
The term of office of members of the House of Representatives shall be four years.
However, the term shall be terminated before the full term is up in case the House of
Representatives is dissolved.
Article 46• Term length of second chamber
The term of office of members of the House of Councillors shall be six years, and
election for half the members shall take place every three years.
Article 47• Electoral districts
• First chamber selection
• Second chamber selection
Electoral districts, method of voting and other matters pertaining to the method of
election of members of both Houses shall be fixed by law. constituteproject.org PDF generated: 27 Jul 2018, 21:09
Page 10Japan 1946
Article 48• Eligibility for first chamber
• Eligibility for second chamber
No person shall be permitted to be a member of both Houses simultaneously.
Article 49
Members of both Houses shall receive appropriate annual payment from the
national treasury in accordance with law.
Article 50
Except in cases provided by law, members of both Houses shall be exempt from
apprehension while the Diet is in session, and any members apprehended before the
opening of the session shall be freed during the term of the session upon demand of
the House.
Article 51• Immunity of legislators
Members of both Houses shall not be held liable outside the House for speeches,
debates or votes cast inside the House.
Article 52
An ordinary session of the Diet shall be convoked once per year.
Article 53• Extraordinary legislative sessions
The Cabinet may determine to convoke extraordinary sessions of the Diet. When a
quarter or more of the total mem

بخشیدن، آمرزیدن

amplify
augment, deepen شدت یا عمق بخشیدن
abject despicable, servile

پست، خفیف، رقت انگیز

alleviate
abate, relieve کاهیدن، تسکین دادن
admonish counsel, reprove

سرزنش کردن، انتقاد کردن

abate
moderate, decrease کاستن، کم شدن
adherent follower, disciple

تابع، پیرو

abound
flourish, proliferate فراوان بودن، وفور داشتن
awkward rude, blundering

سخت و زحمت دار، معذب کننده

abortive
vain, unproductive بی ثمر

abolish
abrogate, annul

ملغی کردن
allay pacify, soothe

تلطیف کردن، نرم کردن

alien
foreigner, outsider بیگانه
acumen awareness, brilliance

تیزهوشی، فراست

authentic
accurate, credible موثق، معتبر
accord agreement, harmony

آکورد، هماهنگی، هارمونی

adhere
comply, observe قبول و پیروی کردن
axiom adage, truism

حقیقت آشکار، اصل

arraign
incriminate, indict احضار کردن
audacity boldness, courage

بی پروایی، جرئت

ascend
climb, escalate بالا رفتن
adversity misfortune, calamity

بدبختی، فلاکت

adamant
stubborn, inflexible یک دنده، غیرمنعطف
acrimony harshness, bitterness

تندی، شدت

adjunct
joined, added الحاقی، ضمیمه
abash disconcert, rattle

دستپاچه یا شرمنده کردن

abjure
forsake, renounce عهد شکستن، برائت جستن
allure entice, fascinate

جذب کردن، شیفتن
کلمات مترادف انگلیسی که با حرف B شروع میشود


کلمه اصلی مترادف انگلیسی معنی
busy active, engaged

مشغول، درگیر

bustle
commotion, tumult شلوغی، هیاهو
brittle breakable, crisp

شکننده

bold
adventurous بی باک، جسورانه، ماجراجو
boisterous clamorous, rowdy

پرسروصدا (معمولا به شکل منفی)

blunt
dull, insensitive کرخت، بی حس
bleak grim, austere

پوچ، غم انگیز

bind
predicament بدبختی، شرایط سخت
bewitching alluring, charming

خوش آمدنی، افسونگر

benign
favorable, friendly دوست داشتنی، نیکو
benevolent benign, generous

نیک سرشت، خوب

befogged
becloud, dim مبهم، مختل
bawdy erotic, coarse

اروتیک

batty
insane, silly احمق، دیوانه
base vulgar, coarse

ناهنجار

barrier
barricade, obstacle مانع
barren desolate, sterile

بی ثمر، تهی

baroque
florid, gilt باروک، دارای طلاکاری و گلگون
barbarous frustrate, perplex

وحشی، گیج و بهت زده

baffle
astound, faze

مبهوت کردن
بیشتر بخوانید:کلمات متضاد انگلیسی
کلمات مترادف انگلیسی که با حرف C شروع میشود
کلمه اصلی مترادف انگلیسی معنی
comic clown, jester

دلقک، مضحک، خنده دار

consequence
effect, outcome پیامد
compassion kindness. Sympathy

همدلی، همدردی

creation
formation, foundation ایجاد، پایه، شکل گیری
cunning acute, smart

زیرک، حقه باز، باهوش

contrary
dissimilar, conflicting مغایر، مخالف
captivate beguile, bewitch

اسیر کردن، افسون کردن

catholic
generic, liberal لیبرال، روشن فکر
cease terminate, desist

متوقف کردن

consent
agree, permit موافقت کردن، اجازه دادن
cement plaster, mortar

گچ، سیمان

conceit
egotism, immodesty خودرایی، غرور، خودپسندی
comprise include, contain

شامل شدن، تشکیل شده بودن از

callous
obdurate, unfeeling سنگدل، بی عاطفه
consolidate centralize, fortify

یکپارچه کردن، محکم ساختن

celebrated
acclaimed, lionized ستوده، مشهور
calm harmonious, unruffled

آرام، هماهنگ

cheap
competitive, inexpensive ارزان
chastise

punish, admonish


تنبیه کردن، مجازات کردن
consolidate solidify, strengthen

یکپارچه کردن، تقویت کردن، محکم ساختن

condemn
castigate, chide محکوم کردن
calamity adversity, misfortune

سانحه، بدبختی، فلاکت

contradict
deny, oppose تضاد داشتن
camouflage cloak, disguise

استتار کردن

contempt
scorn, disregard اهانت، تحقیر
captivate charm, fascinate

افسون کردن، اغوا کردن، جذب کردن

calculating
canny, devious حسابگر، زیرک
concur approve, agree

موافق بودن، هم جهت بودن

clandestine
covert, furtive مخفی، پوشیده
compact bunched, thick

فشرده، ضخیم

compress
abbreviate, shrink فشرده کردن، متراکم کردن
carnal earthly, fleshly

زمینی، مادی

censure
rebuke, reprimand سرزنش و انتقاد شدید کردن
calumny defamation, aspersion

رسوایی، هتک حرمت، بدنامی

courtesy
generosity, reverence شعور و ادب
confident bold, undaunted

جسور و محکم

conspicuous
prominent, obvious آشکار، مشهود
concord agreement, accord

توافق، پیمان، موافقت

captivity
imprisonment, confinement اسارت، گرفتاری
candid blunt, bluff

رک و بی پرده

coarse
bawdy, boorish زشت و قبیح
concede yield, permit

واگذار کردن، اذعان کردن

chaste
virtuous, pure خالص، نیکو، بی شیله پیله
capable competent, able

توانا

classic
simple, typical

کلاسیک، ساده
مترادف کلماتی که با حرف D شروع می شوند
کلمه اصلی مترادف انگلیسی معنی

dissuade
remonstrate, counsel باز داشتن، منصرف کردن
denounce blame, boycott

سرزنش کردن، بایکوت کردن

destructive
catastrophic, pernicious مخرب، فاجعه بار
decipher interpret, reveal

رمزگشایی کردن، فاش کردن

deceit
deception, artifice فریب، حیله، خدعه
deride mock, taunt

تمسخر کردن، دست انداختن

decay
collapse, decompose فساد، خرابی، زوال
docile pliable, pliant

نرم خو، تسلیم شونده، فرمان پذیر

defile
contaminate, pollute آلاییدن، آلوده کردن
deliberate cautious, intentional

عمدی، تعمدی، آگاهانه

dense
opaque, piled مات، مبهم، کدر
defray spend, pay

تسویه کردن، پرداختن

deprive
despoil, divest محروم کردن، سلب کردن
derogatory sarcastic, critical

گستاخانه، بی ادبانه

dwarf
diminutive, petite کوچک، خرد
disdain detest, despise

اهانت، تحقیر کردن، نفرت داشتن

demolish
ruin, devastate نابود کردن
despair depression, misery

بدبختی، بیچارگی
کلمات مترادف انگلیسی که با حرف E شروع میشود
کلمه اصلی مترادف انگلیسی معنی
eclipse diminution, dimming

افول، کاهش در اندازه یا میزان یا اهمیت

encumbrance
hindrance, obstacle بار، مانع، چیزی که شخصی یا چیزی را عقب نگه می دارد
eager keen, acquisitive

مشتاق، علاقه مند

equivocal
uncertain, hazy مبهم
eccentric strange, abnormal

غیرعادی، عجیب و غریب

epitome
precise, example نمونه، مثال
enormous colossal, mammoth

بزرگ، عظیم

eloquence
expression, fluency شیوایی، فصاحت، روانی
ecstasy delight, exultation

شادی و شعف

eradicate
destroy, exterminate حذف کردن، نابود کردن
efface destroy, obliterate

نابود کردن

endeavor
undertake, aspire

تلاش کردن، عهده دار شدن
کلمات مترادف انگلیسی که با حرف F شروع میشود
کلمه اصلی مترادف انگلیسی معنی

frugality
economy, providence صرفه جویی، اقتصادی بودن
feud strife, quarrel

دعوا، درگیری

frivolous
petty, worthless بیهوده، بی معنی
frantic violent, agitated

آشفته، عصبانی و خشن، بهم ریخته

Mental Health and Nature 16
Green, serene and
biodiverse: we benefit
from ‘high quality’ nature
spaces Some evidence suggests that variety within nature (or biodiversity) is an
important factor in maximising its mental health benefits. Biodiversity
throughbird-species richness, followed by plant-species richness, habitat
diversity and butterfly richness are all related to improved wellbeing
(Aerts et al., 2018), increased positive affect (mood) and lower levels of
anxiety (Wolf et al., 2017).
Other data tell us that a ‘serene’ landscape (defined as a place of calm
or silence; often a forest with different varieties of trees, or near a water
course) has a positive impact on our mental health (M. A. van den Bosch
et al., 2015). Large areas covered by vegetation and bird varieties are
linked to lower levels of depression, anxiety, and stress (Cox et al., 2017).
Urban nature can also improve mental wellbeing, for example flowering
plants, water, urban wildlife

and celebrating how
nature brings meaning to life, e.g.
exploring how nature appears in
songs and stories, poems and art,
or by celebrating the signs and
cycles of nature.
05 Compassion
Taking actions that are good
for nature, e.g. creating homes
for nature, and making ethical
product choices.
The pathways provide a flexible
design framework to help bring
about a closer relationship
with nature. These can be
simple changes in the focus of
outdoor activities through to the
design of places to improve the
human-nature relationship on a
larger scale. All because a new
relationship with nature is needed
for a worthwhile and sustainab

People with good nature
connectedness tend to be happier
We benefit from “high
quality” nature spaces
Quality can mean higher
biodiversity (a wide variety of
plants and wildlife). Whether we
are in rural or urban spaces, certain
characteristics of nature are
particularly important.
These include the amount of
’“green’” in trees, plants, and grass,
the variety of plants and wildlife,
and ‘serene’ landscapes that feel
calm and quiet.
Cleanliness, such as the absence
of litter, in nature spaces is also a
factor in how much our mental
health benefits from spending time
outside. Cleaner nature areas are
linked to lower rates of depression.
“High quality”
natural spaces
are better for
us and our
wellbeing.
Green and serene
Research shows that people who
are more connected with nature
are usually happier in life and more
likely to report feeling their lives
are worthwhile.
Nature can generate a multitude
of positive emotions, such as
calmness, joy, creativity and can
facilitate concentration. Nature
connectedness is also associated
with lower levels of poor mental
health; in particular lower depression
and anxiety levels. Perhaps not
surprisingly, people with strong
nature connectedness are also more
likely to have pro-environmental
behaviours such as recycling items
or buying seasonal food.
This is likely to lead to
further benefits, if these pro-
environmental activities can lead
to improvements in nature that
we can then go on to enjoy. At a
time of devastating environmental
threats, developing a stronger
mutually supportive relationship
between people and the
environment will be critical.
Mental Health and Nature 5
@Mentalhealth@Mentalhealth
How connecting with nature benefits our mental health.
@mentalhealthfoundation Nature is everywhere, but
high quality nature isn’t
available equally.
Mental Health and Nature 6
Proximity is certainly a factor, with deprived
communities least likely to live near a high quality
nature space. Perhaps unsurprisingly, our poll found
that people living in urban areas were less likely than
rural residents to connect with nature as much as they
wanted, and people without gardens less likely than
those with gardens.
Younger adults in particular may face many barriers to
connecting with nature. People living with a disability
or health condition often face particular barriers to
access, when natural spaces are not equipped with
inclusion in mind or there is alack of accessible routes.
For some groups, including many women, younger
people, disabled people and people from ethnic
minorities, nature spaces may feel inaccessible or
less enjoyable because they are not safe – from risk
of physical harm, *******ual harassment, hate crime or
discrimination. For many of these groups there is a
double effect of this inequality.
Whilst nature can be found
anywhere, high-quality nature spaces
which we know are most likely to
help support good mental health are
not available equally to everyone in
the UK. This is a more complicated
picture than just how far we live from
a high-quality nature space.
Several groups described above not only get less of
the wellbeing benefit of connecting with nature as a
result of these access barriers, but they are precisely
the groups within our population who are most at risk
of mental health problems.
There are good examples of initiatives in nature spaces
to reduce the inequality of access, and allow all groups
to benefit from connecting with nature to support
their wellbeing.
High quality urban parks, designed with
accessibility in mind, can enable more people to
enjoy and connect with nature. Other solutions
include planting flowers and trees along our streets
or even recreating natural habitats where new
human developments such as a road have been
built. These are known as “green corridors”.
How connecting with nature benefits our mental health.
@Mentalhealth@Mentalhealth@mentalhealthfoundation Conclusions
Mental Health and Nature 7
@Mentalhealth
The key message of this research evidence is
a need to shift our attention from focusing on
getting people to visit natural and sometimes
remote spaces, to focusing on how people can
tune in and connect with ‘everyday’ nature
close to home through simple activities. We
can develop a new relationship with the natural
world by noticing nature, and that doing so has
been found to bring benefits in mental health.
Policy recommendations
01. Facilitating connection with nature
02. Protecting the natural environment and restoring biodiversity
03. Improving access to nature
04. Using the planning system and urban design to improve the visibility
and availability of nature in every local area
05. Making green spaces safe for all
06. Building Developing a life-long relationship with nature
How connecting with nature benefits our mental health.
@mentalhealthfoundation Introduction
01
8
@mentalhealthfoundation @Mentalhealth
Our relationship with nature – how much we
notice, think about and appreciate our natural
surroundings – can be a critical factor in
supporting good mental health alongside other
factors such as how much money we have or what
kind of job we do.
Mental Health and Nature 8
@mentalhealthfoundation @Mentalhealth@Mentalhealth
How connecting with nature benefits our mental health.
@mentalhealthfoundation In this report, we present the latest evidence of how nature impacts
positively on our mental health and why it is important to develop a good
connection with nature and develop our connectedness.
We also include findings from the YouGov poll we have conducted on this
theme specifically for Mental Health Awareness Week.1
We commonly think of “Nature” as referring to
wild plants, animals, ecosystems, landscapes and
waterscapes, in contrast to built environments and
places shaped by human activity.
Nature exists on a spectrum, from wildernesses with
little evidence of human impact to small parks in highly
urbanised areas, from a dandelion or an urban stream,
to extensive woodlands (Bratman et al, 2012).
It is now widely accepted that green features which
are partly the products of human activity, such as
urban parks and back gardens, also represent nature
(McAllister et al, 2017).
Key to how we define nature is our own personal
experience - our perceptions of and/or interactions
with any stimuli from the natural world, for example
listening to birds singing from our window, growing
herbs in our kitchen, looking at nature photos, sitting
in the back garden, going to the local park, feeling
the weather, and noticing the movements of the sun
(Bratman et al, 2019; Miles Richardson et al, 2015).
As we will explore later, ‘nature connectedness’
describes the way we relate to, and experience,
nature. It refers to the kind of relationship we develop
with the natural world. When we have high levels of
nature-connectedness we are often happier in life, feel
our lives are more worthwhile and have lower levels
of depression and anxiety (Capaldi A. etal, 2014;
Richardson et al, 2021).
What do we mean by nature?
Mental Health and Nature 9
@Mentalhealth
Nature has played an important role in
supporting many people’s mental health during
the coronavirus pandemic, and this is one of the
reasons why it has been chosen as the Mental
Health Awareness Week theme for 2021.
How connecting with nature benefits our mental health.
@mentalhealthfoundation
1All figures described as coming from ‘our poll’ are from YouGov Plc. Total sample size
was 4274 UK adults. Fieldwork was undertaken between 6th - 8th April 2021. The
survey was carried out online. The figures have been weighted and are representative
of all UK adults (aged 18+). A new love of nature
during lockdown?
Mental Health and Nature 10
@Mentalhealth
At the Mental Health Foundation,
we have been conducting our own
research on the mental health
impacts of the pandemic. We
have learnt the important role
that nature played in supporting
many people’s mental health at
this time. In that study, people of
all ages (except teenagers – more
on this later) told us that us that
visiting green spaces, such as
parks was one of the top coping
strategies and 45% of the UK adult
population used this to cope with
the stress of the pandemic and
its restrictions.
Other studies have likewise found
that different levels of lockdown
restrictions have had negative
consequences on people’s mental
health, but that contact with nature
has helped people to cope (Soga
et al, 2020). During the pandemic,
many people turned to nature,
visiting nature spaces more often
and being more likely to notice the
nature that is all around us.
In fact, the increase in noticing
nature was much greater than
the increase in time spent in
nature. Between April and June
2020, fewer than half of adults
reported they were spending
more time outside, but three
quarters reported they were
noticing and engaging with
everyday nature more (Natural
England, 2020). And studies
showed that these changes in
the relationship with nature
contributed to improvements in
people’s wellbeing; particularly in
feelings of life being worthwhile
(M Richardson & Hamlin, 2021).
At the Mental Health Foundation,
we therefore believe that
connecting with and developing
a close relationship with nature
can help to promote good mental
health, and that nature can act as a
protective factor for good mental
health.
of UK adults surveyed in
our YouGov poll said that,
connecting with nature has been
important in terms of managing
their mental health during the
pandemic.
73%
of UK adults had connected less
with nature during the pandemic
18%
of UK adults had connected more
with nature during the pandemic
34%
By green spaces we mean any nature area that
is predominantly green in colour such as parks,
woodland or forests. By blue spaces we mean any
nature area that is predominantly blue in colour
such as rivers, wetlands, beaches or canals.
How connecting with nature benefits our mental health.
@mentalhealthfoundation Nature as a
protective factor for
good mental health
02
Mental Health and Nature 11
@Mentalhealth
How connecting with nature benefits our mental health.
@mentalhealthfoundation@mentalhealthfoundation@mentalhealthfoundation Mental Health and Nature 12
@Mentalhealth
Intuitively, most of us feel that spending time
in nature is good for our wellbeing. Whilst
inequalities and barriers mean that by no means
everyone is currently able to connect with nature
in the optimal way (see section 3 below).
This is fully backed-up by research
evidence, which consistently shows
that nature has a beneficial impact on
our mental health. The relationship we
develop with nature is emerging as an
important protective factor for our
mental health.
Studies have found that wellbeing can be linked, in part, with how close we
live to nature spaces and street trees or private gardens, in both urban and
rural settings (Jiricka-Pürrer et al., 2019; Kruize et al., 2020).
Spending time in blue spaces and green spaces is linked to improved life
satisfaction, reduced anxiety and increased happiness (McMahan & Estes,
2015). Contact with nature generates an increase in positive emotions and
feelings of vitality, and a decrease in negative emotions; it also provides
relief of from mental tiredness, and an improvement in our attention span
(Lackey et al., 2019).
Furthermore, research in different contexts demonstrates the positive
effects of being exposed to nature. In the workplace, for example, people
with ‘high exposure’ to nature (taking more frequent breaks to spend time
outdoors in green spaces) reported significantly higher work engagement
compared to the participants in the same study who described themselves
as having a low ‘exposure to nature’ profile (tho