Nanotechnology

Nanotechnology, the creation and use of materials or devices at extremely small scales.
These materials or devices fall in the range of 1 to 100 nanometers (nm). One nm is equal
to one-billionth of a meter (.000000001 m), which is about 50,000 times smaller than the
diameter of a human hair. Scientists refer to the dimensional range of 1 to 100 nm as the
nanoscale, and materials at this scale are called nanocrystals or nanomaterials.


                  The nanoscale is unique because nothing solid can be made any smaller.
It is also unique because many of the mechanisms of the biological and physical world
operate on length scales from 0.1 to 100 nm. At these dimensions materials exhibit
different physical properties; thus scientists expect that many novel effects at the
nanoscale will be discovered and used for breakthrough technologies.

                  A number of important breakthroughs have already occurred in nanotechnology.
These developments are found in products used throughout the world. Some examples are catalytic
converters in automobiles that help remove air pollutants, devices in computers that read from
and write to the hard disk, certain sunscreens and cosmetics that transparently block harmful
radiation from the Sun, and special coatings for sports clothes and gear that help improve the
gear and possibly enhance the athlete’s performance. Still, many scientists, engineers, and
technologists believe they have only scratched the surface of nanotechnology’s potential.

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Wireless Communation

Wireless Communications, various telecommunications systems that use radio waves to carry signals
and messages across distances. Wireless communications systems include cellular telephones, pagers,
radio telegraphs, satellite telephones, laptop computers, personal digital assistants (PDAs), shortwave
radios, and two-way radios. They are used primarily to transmit private communications. Commercial radio
and television are also wireless telecommunications systems, but radio and television are mainly public
broadcast services rather than private communications systems (see Radio and Television Broadcasting).
This article focuses on wireless communications systems that are used primarily for private communications.

                           Wireless communications allow people greater flexibility while communicating,
because they do not need to remain at a fixed location, such as a home or office, but instead can communicate
with other people while traveling in a car or walking along a street. Wireless technologies make communications
services more readily available than traditional wire-based services (such as ordinary telephones), which require
the installation of wires in fixed locations. Wireless communications devices are useful in places where communications
services are only temporarily needed, such as at outdoor festivals or large sporting events. These technologies are also
useful for communicating in remote locations, such as mountains, jungles, or deserts, where wire-based telephone service might not exist. Police, fire, and other emergency departments use wireless devices, such as two-way radio, to communicate information between vehicles that are already responding to emergency calls. Construction and utility workers frequently use handheld radios for short-range communication and coordination. Many businesspeople use wireless devices, such as cellular radio telephones, also known as cell phones, to stay in contact with colleagues and clients while traveling. Increasingly, people are using wireless devices for a variety of everyday purposes.
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Cmputer

The Computer is one of the wonderfull invention of morden science and techology.
Computer is an electrinic device tha compute,manipulate and summon the large
anomout of the informaions much very fast that the human can do mannulay.
In aother words, It is an electronic device that calcultes, manipulates and stores
large amount of data or informaions. Very beging people had no facility to keep
record their things. They used to keep their record by collecting pice of stone or
wood. With passage of time, people have deveoped the things that are automated and
sekf controled. A Computer has become very necessary things of the human life.It can
the job in few second that take an hour to do mannualy by human.
                       
                           Computer has become a part of morden socirty. It has great
impacrt on morden society of 21st century. It is taken as necessary goods for daly life.
Like other it also is characterised with merits and demerits. Having a computer has many
advantages.People use computers in many ways. In business, computers track inventories
with bar codes and scanners, check the credit status of customers, and transfer funds
electronically. In homes, tiny computers embedded in the electronic circuitry of most
appliances control the indoor temperature, operate home security systems, tell the time,
and turn videocassette recorders (VCRs) on and off. Computers in automobiles regulate
the flow of fuel, thereby increasing gas mileage, and are used in anti-theft systems.
Computers also entertain, creating digitized sound on stereo systems or computer-animated
features from a digitally encoded laser disc. Computer programs, or applications, exist
to aid every level of education, from programs that teach simple addition or sentence
construction to programs that teach advanced calculus.

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Morden Technology

By the end of the Middle Ages the technological systems called cities
had long since become a central feature of Western life. In 1600 London
and Amsterdam each had populations of more than 100,000, and twice that
number resided in Paris. Also, the Dutch, English, Spanish, and French
were beginning to develop global empires. Colonialism and trade produced
a powerful merchant class that helped to create an increasing desire for
such luxuries as wine, coffee, tea, cocoa, and tobacco. These merchants
acquired libraries, wore clothing made of expensive fabrics and furs, and
set a style of life aspired to by the wider populace. By the beginning of
the 18th century, capital resources and banking systems were well enough
established in Great Britain to initiate investment in mass-production
techniques that would satisfy some of these middle-class aspirations.
                            The Industrial Revolution started in England,
because that nation had the technological means, government encouragement,
and a large and varied trade network. The first factories appeared in 1740,
concentrating on textile production (see Factory System).
                             One of the most important innovations in the
weaving process was introduced in France in 1801 by Joseph Jacquard; his
loom used cards with holes punched in them to determine the placement of
threads in the warp. This use of punched cards inspired the British
mathematician Charles Babbage to attempt to design a calculating machine
based on the same principle.

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The Earliest Technology

The earliest known human artifacts are roughly flaked stones used for chopping and
scraping, found primarily in eastern Africa. Known as Oldoman tools, they date from
about 2.3 million years before present, and serve to define the beginning of the
Stone Age. The first toolmakers were nomadic groups of people who used the sharp
edges of stone to process food. By about 40,000 years before present, humans had
begun to use fire and to make a variety of tools, including pear-shaped axes, scrapers,
knives, and other instruments of stone, bone, and other materials. They had also
begun to use tools to make clothing and build shelters for protection from inclement
weather. The use of tools can be observed in many members of the animal kingdom, but
the capacity for creating tools to craft other objects distinguishes humans from all
other animals.

                      The next big step in the history of technology was the control
of fire. By striking flint against pyrites to produce sparks, people could kindle fires
at will, thereby freeing themselves from the necessity of perpetuating fires obtained
from natural sources. Besides the obvious benefits of light and heat, fire was also
used to bake clay pots, producing heat-resistant vessels that were then used for cooking
grains and for brewing and fermenting. Fired pottery later provided the crucibles in which
metals could be refined.

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Dfintion of Tecnology

Technology, general term for the processes by which human beings fashion
tools and machines to increase their control and understanding of the
material environment. The term is derived from the Greek words 'tekhne',
which refers to an art or craft, and logia, meaning an area of study;
thus, technology means, literally, the study, or science, of crafting.

Many historians of science argue not only that technology is an essential
condition of advanced, industrial civilization but also that the rate of
technological change has developed its own momentum in recent centuries.
Innovations now seem to appear at a rate that increases geometrically,
without respect to geographical limits or political systems. These
innovations tend to transform traditional cultural systems, frequently
with unexpected social consequences. Thus technology can be conceived
as both a creative and a destructive process.

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Television

Television, system of sending and receiving pictures and sound by means of electronic signals
transmitted through wires and optical fibers or by electromagnetic radiation. These signals are
usually broadcast from a central source, a television station, to reception devices such as
television sets in homes or relay stations such as those used by cable television service
providers. Television is the most widespread form of communication in the world. Though most
people will never meet the leader of a country, travel to the moon, or participate in a war,
they can observe these experiences through the images on their television.

                        Television has a variety of applications in society, business, and science.
The most common use of television is as a source of information and entertainment for viewers in
their homes. Security personnel also use televisions to monitor buildings, manufacturing plants,
and numerous public facilities. Public utility employees use television to monitor the condition
of an underground sewer line, using a camera attached to a robot arm or remote-control vehicle.
Doctors can probe the interior of a human body with a microscopic television camera without having
to conduct major surgery on the patient. Educators use television to reach students throughout the world.

                      People in the United States have the most television sets per person of any country,
with 835 sets per 1,000 people as of 2000. Canadians possessed 710 sets per 1,000 people during the same year.
Japan, Germany, Denmark, and Finland follow North America in the number of sets per person.

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Telephone

Telephone, instrument that sends and receives voice messages and data. Telephones convert
speech and data to electrical energy, which is sent great distances. Modern technology has
made the telephone much more portable, convenient, and versatile. Lightweight, handheld cell
 phones make it possible to place and receive calls on-the-go in many locations and at any time.
Traditional telephones now link with radio, Internet, and satellite services as part of global
telecommunications.

                         Telephones play a vital role in business and the economy, as well as
in the personal and family lives of individuals. Telephones also save lives and provide security
by making it possible to summon help quickly in an emergency (as in the 911 service in the United States)
and contact law enforcement or medical services. The telephone has other uses that do not involve one
person talking to another. Instead, an automated menu can allow a caller to pay bills, obtain prerecorded
information, or retrieve messages from an answering machine. In 2004 there were 606 main telephone lines
per 1,000 people in the United States and 566 main telephone lines per 1,000 people in Canada.

                    About half of the information passing through telephone lines occurs entirely between
special-purpose telephones, such as computers with modems. A modem converts the digital bits of a computer’s
output to an audio tone, which is then converted to an electrical signal and passed over telephone lines
to be decoded by a modem attached to a computer at the receiving end. Another special-purpose telephone is
a facsimile machine, or fax machine, which produces a duplicate of a document at a distant point.

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Telecommunications

Telecommunications, devices and systems that transmit electronic or optical signals across
long distances. Telecommunications enables people around the world to contact one another,
to access information instantly, and to communicate from remote areas. Telecommunications
usually involves a sender of information and one or more recipients linked by a technology,
such as a telephone system, that transmits information from one place to another.
Telecommunications enables people to send and receive personal messages across town, between
countries, and to and from outer space. It also provides the key medium for delivering news,
data, information, and entertainment.

                     Telecommunications devices convert different types of information, such
as sound and video, into electronic or optical signals. Electronic signals typically travel
along a medium such as copper wire or are carried over the air as radio waves. Optical signals
typically travel along a medium such as strands of glass fibers. When a signal reaches its
destination, the device on the receiving end converts the signal back into an understandable
message, such as sound over a telephone, moving images on a television, or words and pictures
on a computer screen.

                      Telecommunications messages can be sent in a variety of ways and by
a wide range of devices. The messages can be sent from one sender to a single receiver
(point-to-point) or from one sender to many receivers (point-to-multipoint). Personal
communications, such as a telephone conversation between two people or a facsimile (fax)
message (see Facsimile Transmission), usually involve point-to-point transmission.
Point-to-multipoint telecommunications, often called broadcasts, provide the basis for
commercial radio and television programming

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Science And Technology

The meanings of the terms science and technology have changed significantly
from one generation to another. More similarities than differences, however,
can be found between the terms.

               Both science and technology imply a thinking process, both are
concerned with
causal relationships in the material world, and both employ an experimental
methodology that results in empirical demonstrations that can be verified by
repetition (see Scientific Method). Science, at least in theory, is less
concerned with the practicality of its results and more concerned with the
development of general laws, but in practice science and technology are
inextricably involved with each other. The varying interplay of the two
can be observed in the historical development of such practitioners as
chemists, engineers, physicists, astronomers, carpenters, potters, and
many other specialists. Differing educational requirements, social status,
vocabulary, methodology, and types of rewards, as well as institutional
objectives and professional goals, contribute to such distinctions as can
 be made between the activities of scientists and technologists; but throughout
history the practitioners of “pure” science have made many practical as well as
theoretical contributions.

                       Indeed, the concept that science provides the ideas for
technological innovations and that pure research is therefore essential for any
significant advancement in industrial civilization is essentially a myth. Most
of the greatest changes in industrial civilization cannot be traced to the laboratory.
Fundamental tools and processes in the fields of mechanics, chemistry, astronomy,
metallurgy, and hydraulics were developed before the laws governing their functions
were discovered. The steam engine, for example, was commonplace before the science of
thermodynamics elucidated the physical principles underlying its operations.

                    In recent years a sharp value distinction has grown up between
science and technology. Advances in science have frequently had their bitter opponents,
but today many people have come to fear technology much more than science. For these
people, science may be perceived as a serene, objective source for understanding the
eternal laws of nature, whereas the practical manifestations of technology in the modern
world now seem to them to be out of control.

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Radio

Radio, system of communication employing electromagnetic waves propagated through space.
Because of their varying characteristics, radio waves of different lengths are employed
for different purposes and are usually identified by their frequency. The shortest waves
have the highest frequency, or number of cycles per second; the longest waves have the
lowest frequency, or fewest cycles per second. In honor of the German radio pioneer Heinrich
Hertz, his name has been given to the cycle per second (hertz, Hz); 1 kilohertz (kHz) is 1000
cycles per sec, 1 megahertz (MHz) is 1 million cycles per sec, and 1 gigahertz (GHz) is 1 billion
cycles per sec. Radio waves range from a few kilohertz to several gigahertz. Waves of visible light
are much shorter. In a vacuum, all electromagnetic waves travel at a uniform speed of about 300,000
km (about 186,000 mi) per second. For electromagnetic waves other than radio, see Electromagnetic Radiation.

                         Radio waves are used not only in radio broadcasting but in wireless telegraphy,
two-way communication for law enforcement, telephone transmission, wireless Internet, television, radar,
navigational systems, GPS, and space communication. In the atmosphere, the physical characteristics of
the air cause slight variations in velocity, which are sources of error in such radio-communications
systems as radar. Also, storms or electrical disturbances produce anomalous phenomena in the propagation
of radio waves. See Wave Motion.

                       Because electromagnetic waves in a uniform atmosphere travel in straight lines
and because the earth's surface is approximately spherical, long-distance radio communication is made
possible by the reflection of radio waves from the ionosphere. Radio waves shorter than about 10 m
(about 33 ft) in wavelength—designated as very high, ultrahigh, and superhigh frequencies
(VHF, UHF, and SHF)—are usually not reflected by the ionosphere; thus, in normal practice,
such very short waves are received only

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