the nature of technology brian arthur pdf
teaching about evolution and the nature of science nap 2004 pdf
Ngày tải lên :
27/06/2014, 18:20
... to
show the relative positions and movements
of the sun, planets, and moon as they cir-
cled the earth. As the center of the uni-
verse, the earth was a sphere in the center
of the orrery. The other ... of
the last two centuries has been the discovery
of the vast expanse of geologic time. Early
methods of calculating the age of the earth
relied on measures of the rate of sedimenta-
tion or the ... movements of the planets
given the laws of motion that Newton
derived. As a result of the steady accumu-
lation of evidence, the theological interpre-
tation of celestial movements gave way to
the...
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An Encyclopedia of the History of Technology part 7 pdf
Ngày tải lên :
04/07/2014, 01:20
... copper.
Smelting of oxide and carbonate copper ores
It seems that towards the end of the fourth millennium BC, the supplies of native
copper accessible to the ancient world were incapable of satisfying ... well below their melting point to soften them after
cold forging, or in the furnaces where crystals were melted together.
Apart from gold, silver and the other noble metals, copper is the only ... think for themselves. This is a concept that to
many people appears ridiculous and to many others a threat to the dignity of
themselves as members of the human race or worse, a threat to the very
existence...
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An Encyclopedia of the History of Technology part 13 pdf
Ngày tải lên :
04/07/2014, 01:20
... Salindres to reduce the
melting point and viscosity of the slag, and to dissolve the thin layers of
alumina which formed on the surface of the reduced globules of aluminium,
thus enabling them to coalesce. ... furnace. The
furnace charge consisted of 100kg (220lb) of the double chloride, 45kg (99lb)
of cryolite and 35kg (77lb) of sodium. The function of the cryolite was to act
as a flux and dissolve the ... a very high thermal
conductivity. This encouraged its use for cooking utensils. The first
authenticated use of aluminium as a roofing material is provided by the dome
of the Church of San Gioacchino...
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An Encyclopedia of the History of Technology part 19 pdf
Ngày tải lên :
04/07/2014, 01:20
... one above the other to prevent loss of gas. The top bell
is opened and the raw materials fall on the lower one, which is closed and
sealing the furnace. Then the top bell is closed and the bottom ... production. The wrought iron balls as they came from the
furnace were always hammered out into a bloom, but the next stage depended
on the grade of iron being made.
Figure 2.2: The product of the puddling ... When the pig iron was brought up to melting
point, some of it formed magnetic oxide (Fe
3
O
4
) which made slag with the
silica in the sand lining of the furnace. This was the source of the waste;...
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An Encyclopedia of the History of Technology part 44 pdf
Ngày tải lên :
04/07/2014, 01:20
... diameter the operator tried the gauge which
should pass the ‘Go’ anvil but not pass the ‘No Go’ end. The difference in the
anvil dimensions is the tolerance allowed on the dimension to which the part
... dimensional
standards for the whole world by 1926 and he is referred to as the ‘Master of
Measurement’. The use of gap gauges also became common for the inspection
of screw threads based on the idea of William ... these industries. With the coming of
the motor industry this firm grew to become one of the most famous machine
tool manufacturers in the world, Alfred Herbert Ltd. Frederick Lanchester was
the...
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An Encyclopedia of the History of Technology part 47 pdf
Ngày tải lên :
04/07/2014, 01:20
... protection against the weather for
the rider. The design of the moped originated in the folding scooters such as
the Corgi used by paratroops during the war.
Another development of the same period, ... to the diamond-
shaped frame of the ‘safety’ pedal bicycle. Coventry was again the centre of the
industry which really took off with the repeal of the ‘Red Flag’ Act in 1896, a
maximum speed of ... for some years, was the
bubble-car. Heinkel and Messerschmitt were both prominent makes of these
machines, the designs of which owed much to the cockpits of the aircraft
which these companies had...
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An Encyclopedia of the History of Technology part 53 pdf
Ngày tải lên :
04/07/2014, 01:20
... and their size
increased. It was further improved in the 1880s but the construction in the 1950s
of the St Lambert and Côte Ste Catherine locks on the St Lawrence Seaway
spelled the end of the ... In the south also at the beginning of the
eighteenth century, a start was made on linking the Volga and the Don so that
traffic could go to either the Black Sea or the Caspian Sea.
At the end of ... from the upper level above the power station on to
the crest of the dam and a second plane lowering the boats into the tail water
PART THREE: TRANSPORT
506
when the vital importance of the canal...
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Tài liệu LUYỆN ĐỌC TIẾNG ANH QUA TÁC PHẨM VĂN HỌC-THE ADVENTURES OF SHERLOCK HOMES -ARTHUR CONAN DOYLE 2-2 pdf
Ngày tải lên :
15/12/2013, 14:15
... divined in the
cellar of the City branch of one of the principal London banks. Mr.
Merryweather is the chairman of directors, and he will explain to you that
there are reasons why the more daring ... "it was perfectly obvious
from the first that the only possible object of this rather fantastic business of
the advertisement of the League, and the copying of the Encyclopaedia, must
be to ... rogue has the temporary
office, the other rogue incites the man to apply for it. and together they
manage to secure his absence every morning in the week. From the time that
I heard of the assistant...
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Tài liệu LUYỆN ĐỌC TIẾNG ANH QUA TÁC PHẨM VĂN HỌC-THE ADVENTURES OF SHERLOCK HOMES -ARTHUR CONAN DOYLE 8-3 pdf
Ngày tải lên :
24/12/2013, 20:15
... how we broke the sad news to the
terrified girl, how we conveyed her by the morning train to the care of her
good aunt at Harrow, of how the slow process of official inquiry came to the
conclusion ... data.
The presence of the gypsies, and the use of the word 'band,' which was used
by the poor girl, no doubt to explain the appearance which she had caught a
hurried glimpse of by the ... laid it on the corner of the table.
Holmes had brought up a long thin cane, and this he placed upon the bed
beside him. By it he laid the box of matches and the stump of a candle. Then
he...
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Tài liệu LUYỆN ĐỌC TIẾNG ANH QUA TÁC PHẨM VĂN HỌC-THE ADVENTURES OF SHERLOCK HOMES -ARTHUR CONAN DOYLE 9-1 pdf
Ngày tải lên :
22/01/2014, 01:20
... from the very heads of your profession.
Still, of course, if you would like to draw out of the business, there is plenty
of time to do so.'
"I thought of the fifty guineas, and of ... during the years of our intimacy, there were only two
which I was the means of introducing to his notice that of Mr. Hatherley's
thumb, and that of Colonel Warburton's madness. Of these ... cold, dank grasp, he hurried from the
room.
THE ADVENTURES OF SHERLOCK HOMES
ARTHUR CONAN DOYLE
The Adventure of the Engineer's Thumb
Of all the problems which have been submitted...
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Tài liệu LUYỆN ĐỌC TIẾNG ANH QUA TÁC PHẨM VĂN HỌC-THE ADVENTURES OF SHERLOCK HOMES -ARTHUR CONAN DOYLE 9-2 pdf
Ngày tải lên :
22/01/2014, 01:20
... mouth. It was the clank of the levers and the swish of the leaking
cylinder. He had set the engine at work. The lamp still stood upon the floor
where I had placed it when examining the trough. ... into the darkness.
"I glanced at the books upon the table, and in spite of my ignorance of
German I could see that two of them were treatises on science, the others
being volumes of poetry. ... on. The ceiling
of this small chamber is really the end of the descending piston, and it comes
down with the force of many tons upon this metal floor. There are small
lateral columns of water...
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The use of technology by the elderly pdf
Ngày tải lên :
28/03/2014, 19:21
... of the by the Statistical Office of
Finland showed that 30% of the elderly
women used washing machines, whereas 7%
of men used these electrical devices
14
.
According to the results of the ... devices
were in perfect line with the level of
perception of the elderly.
From the results of the present study,
it is evident that the use of new technologies
by the elderly population significantly ... ignored the services
and opportunities provided by the machines
of this type. On the contrary, 5.9% of
participants reported that they were aware
of all the services and capabilities of ATMs.
The...
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Báo cáo khoa học: Monitoring the prevention of amyloid fibril formation by a-crystallin Temperature dependence and the nature of the aggregating species pdf
Ngày tải lên :
30/03/2014, 04:20
... by 0.0167 gặcm
)3
, from the start
of the experiment. By the end of the measurement, the
thickness had increased by 0.342 nm, the mass had
increased by 0.10 ngặmm
)2
and the density had
decreased ... fluores-
cence. The subsequent plateau phase is associated with
a decrease in the concentration of small species, or the
aggregation and precipitation of fibrils [37]. The kinet-
ics of these three stages of ... min. In the main, the pres-
ence of a-crystallin significantly decreased formation of
this large aggregate. As a result of the interaction of
a-crystallin with reduced j-casein, a complex of similar
mass...
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