Prezentace aplikace PowerPoint

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a many-sided element
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Water and Life
Water is very simple, but it behaves as no
other material and it has got some special
qualities. Because of these qualities waters
essential for life. Without it, life couldnt
exist. It couldnt exist on the Earth and
anywhere in the space. Therefore water is
considered an essential requirement of life.
The first living organisms appeared on the
Earth about four billion years ago. They lived in
water which protected them from the ultra-violet
radiation.
The first living organisms left the sea much
later, about half a billion years ago. They took
the water in  themselves and stayed dependent on
it. Water creates about two thirds of our own
bodies.
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Sea water
The sea water is 95 of the total amount of
water in the world. There are some dissolved
substances in the sea water and salt is 99 of
them. In the tropical sea the content of salt
is the highest because a bigger amount of water
is vaporized than it gets back.
Atributes of sea water colour -  the shade of
the water is influenced by the absorbing sun
shine and sky coulour, depends on the content of
plankton and on depth. Possible colours  - blue
there is little plankton in the water - green
and red there are lots of living organisms in
the water - yellow and brown these are colours
of the border seas, to which rivers bring
minerals
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Fresh Water
How much freshwater is there in the world?
Decreasing reserves of fresh water can
result in great problems in the world. They can
appear in Africa in drainage area of the Nile,
in Asia by the Tigris, the Euphrates and the
Ganga rivers and Aral lake which used to
be the forth largest inland sea and which
decreased its area into less than 50 of its
original size due to human activities. Chad
lake, which lies on the border of four
countries (Nigeria, Cameroon , Niger and Chad)
and makes possible life of millions of people
in Africa, looses its water too.Today its area is
1350 km2, but in the year 1963, it was 2500km2.
The reasons of loosing water are global
warming and climatic phenomenon called El
Nino. They result in the desert increase.
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Three States of Water
The state or the stadium of water is a form of
the substance, which has got characteristic
ordering of the particles in the substance and
expresses some typical features. The particle is
a very small part of the substance which has
got some characteristic features (energy,
weight, electric charge, spin, chemical
reactivity, life span etc.).
We distinquish three states of water solid
state (ICE), liquid state (WATER) and gaseous
state (VAPOUR)
Vapour
LIQUEFACTION
DESUBLIMATION
VAPORIZATION
SUBLIMATION
SOLIDIFICATION
Ice
Water
FUSION
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Some Water Animals
Why sharks dont drown in the water?
Shark is heavier than water and so it should
sink to the bottom. To prevent this they havent
got air bladders as other fish, they have got oil
liver. Oil carries the shark, because it is
lighter than water. They have so much oil in the
liver they would fill up five big buckets.
Why dont cephalopods give up before fight ?
Cephalopods are very strong. They usually grow
up 20 meters and they dont give up before
fight. At first they try to escape in an inky
cloud, which they leak as a smoke screen or
they turn to the sperm whale and fight back not
to be caught. Both animals usually fight untill
one of them dies.
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Some Water Animals
Do the seals feel cold?
Seals are warm-blooded mammals. They create
and keep fixed body temperature. They can keep
it even though they often swim in very cold
water. Seals have short hairs or a fur. Under the
skin they have got fat. When they swim in warmer
water, sometimes they warm themselves up too much
and they wave their flippers in the air to cool
down.
Does the electric ray give electric shock?
Electric ray has got special muscles in its body
which can make electric current of 200 volts.
As soon as it attacks fish it kills it
with the electric current. The discharge is
strong enough to knock out a human when he steps
on an electric ray.
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Energy from Water
Water belongs to the unfailing sources
of energy, therefore the production of energy
from water is ecological. The energy from
water is used in the water power stations. In
all power stations except of the sunny power
stations the production of energy is based
on a generator, which is turbine powered.
Turbine
Turbine is an equipment, which is constructed for
effective transposition of the kinetic energy,
which is supplied either by steam or water, into
rotation. There are different types of turbines,
perhaps the best known and most widespread is
Francis turbine, which is used either for
horizontal or vertical direction. Francis
turbine is an eguipment which consists of a
stator and a rotor. After the energy gets on
the shaft of the rotor it begins spinning
and the electric current is induced.
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Sailboats
The antic sailboats were built according to
phoenician patterns, short, wide with tall sides,
a spar in the middle of the deck, operated with
one or two wide oars.  In 3rd century Vikings
started to organize voyages and robberies. Their
ships were eqipped with a spar sheet, the hull
in the shape of the letter V. Their duration was
from 30 to 50 metres, they had 20 pairs of oars.
On the voyages across the ocean Portuguese
sailboats started to be used. They were 15-20
meters long, light and fast. They had sheetss,
which enabled them to sail up the wind. In
15th century a new type of ship appeared in
Spain. It was called galeona. This ship was 40
meters long and 12 meters wide with 3 or 4
spars. Later the sailboats were replaced
by steamships, liners and ferriess.
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Steamships
In 1807 Robert Fulton built the first
steamship for transport of people (North River
Steamboat of Clermont). About 50 passengers could
go on its board. In 1812 a steamship Cemet was
able to sail at the speed of 7 knots. In 1820
it wrecked. In 1829 a Czech inventor Josef
Ressel patented his boat wood-screw.
Break occurred in 1845, when J.K.Brunel launched
a business steamship called Great Britain for
360 passsengers. From 1900 to the 1914 the
biggest stemships for transport of people were
built. Their lonqitude was over 200 metres and
they could transport more than 4000 people.
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Submarines
  The first sketch and description of
submarine was presented by a Venice army
engineer Robert Valurio in 1472. The first
manufactured submarine was just a toy. In 1620 a
Dutch doctor and inventor Cornelius van Drebbel
constructed it . It was built from wood and was
protected by oily skin. American David Bushell
designed a one-seat submarine Turtle. It
consisted of two iron hemispheres. In 1800
Robert Fulton presented a submarine Nautilus.
It was hand-operated and it could sail for 4,5
hours under water. First sumbarine driven by
an electric motor was bulit in 1884 by a Polish
designer Drzewiecki for tsar Alexandr 3. It was
equiped by a scope and 2 bombs .In 1910 a
diesel-elektric motor was constructed and was
used in submarines. During World War II
submarines were widely used and their equipment
(for example a radar) improved .
Batyscape
It is an undersea craft with its own gear
which is used for exploring the extreme
depths. It consists of a spherical cabin for
observation, a system of floats and balast
which help the batyscape to move up and down..
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Cleaness of Water
Human activities cause pollution of water and
also destroy life in it. The pollution is caused
by industrial waste, oil spots, motor oil which
gets to to drainage etc. FARMINGWorldwide 70
of water is used for irrigation. Chemicals such
as pesticides and animal waste decrease the
quality of water. In some rivers and lakes the
amount of oxygen is so low, that no water life
is possible there.
INDUSTRYOur water flows are polluted by
industrial production for example of aluminium,
steel or plastic. Wood-working industry
partakes on decreasing area of the tropical rain
forest. HOUSEHOLDSIn the regions where water
supplies are big enough people often waste
water. Average annual consumption of water
in an ordinal household is 200 000 litres. In
our households, a big amount of chemicals is
used colours, glues, oils and detergents.If
they are poured to the waste water they get to
the rivers, lakes and seas.
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Rivers in Our Region
River Svratka The spring of the
Svratka river is in the Ždárs hills. The river
is 152 km long. There are three dams on the
Svratka river. They are sources of drinkable
water. The stream-bed of the river is quite
narrow. In the valley of the Svratka river some
castles, churches and monasteries were built in
the Middle Ages .
River Svitava The spring
of the Svitava river is in Javorník near
Svitavy. The river is 73 km long. In the
upper part down to Letovice there are a lot of
weirs. The Svitava is a source of drinkable
water. The Svitava has an inflow of of the
Punkva river. It runs through the Moravian Karst.
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Floods in our Region
Water a simple word, which is known by every
one. It is necessary for our lives. It refreshes,
cures, but it is also a wild element which is
very difficult to escape from.
About 8 years ago we faced descructive floods in
Moravia and in 2002 water showed us its
incredible power again. During holidays, in July
2002, on various places of our republic thick
black clouds with rain storms began to appear.
That time some local claims were caused. But
the worst damages were caused by the wild
water element in August 2002.
Some people uselessly risked their lives.
They did not want to help rescuers,
they stayed in their houses and  some hours
later they had to be saved by helicopters.
There were many cases of people loosing
their houses which fell down in the flood and a
few houses which fell down in the flood and a
few people lost even their own lives.
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Dams in our Region
Near Brno we can find Knínickys dam
named after a flooded village Knínicky. It is
situated on the Svratka river about 8 km
northwest of the Brno centre. The concrete
dam is 34,5 m high and 120 m long. There are
about 21 million m3 of water in the reservoir.
The dam is an important recreation centre of
Brno city . That is why there are various stands
and fast foods as well as sport centres. The
lake is suitable for yachting and windsurfing.
The idea of building a dam appeared in the
beginning of 20th century. It should be a
protection from the annual floods on the Svratka
river, a source of the electrical energy, a
source of drinking water and a recreational
centre..
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Ingrid
Zdenek
Monika
David
Jakub
Jana
We have chosen a name of the friendly water
animal as the maskot of our team. But there is
one important difference between seals and
us unfortunately there is no sea in the country
where we live.