Google
 

Saturday, February 24, 2007

Nanotechnology

Nanotechnology entered the more public arena in 2001 when President Clinton
brought worldwide attention to nanotechnology through his budget approval for the
US National Nanotechnology Initiative (NNI). The initial budget allocated for
nanotechnology in 2001 was $422 million, which demonstrated the anticipated
relevance of nanotechnology to the USA economic growth as well as nanotechnology’s
strategic importance to national security. Three years later, in December
2003, President Bush signed the 21st Century Nanotechnology Research and
Development Act, which allocated a budget of $849 million to the NNI, doubling
the initial budget from 2001. After the clear message of commitment of the United
States to nanotechnology since 2001, governments around the world reassessed
their current national nanotechnology policies or finally began to develop their own
focused long-term position in nanotechnology. Since then national government
investments into nanotechnology have increased to over $3 billion worldwide in
2003. A number of state governments have started to implement their nanotechnology
support in addition to the already existing, substantial national government
funding, bringing the public funding for nanotechnology up to an estimated total
of $4 billion. Investment by industry alone is estimated to have added another
$1 billion in 2003 (APNF).
What is it that nanotechnology to offer that has prompted governments and
industry alike to commit substantial funds to a technology which science geeks
started to talk about only a few years ago? What is nanotechnology bringing to the
innovation table that cannot be ignored by financial and economic planners?
Nanotechnology aims to master engineering at the nanometre scale. Nanotechnology
deals with the engineering at a size scale that is currently challenging the entire
semiconductor industry in its effort to further miniaturize chip design. It is working
at a scale which is so familiar and natural to the biotechnology industry since its
own inception. What sets nanotechnology aside from biotechnology is that
nanotechnology in addition to biological building blocks also deals with the
engineering and controlling of building blocks of any inorganic as well as mixed
biological/inorganic building blocks at the nano-scale (natural and/or artificial
origin). Mastering of technology at this size scale has the potential of being able
to customize any thinkable type of material the way we want it to be or to create
properties which only a few years ago were thought not to be in reach in the near
future.
Will this then introduce a new generation of gadgets more powerful and more
versatile than the ones we have just bought? The answer is yes, but it is only a
partial yes since the (electronic) gadgets industry will take some time (6–10 years)
until it will have mastered the mass production of nano-engineered based components.
Nanotechnology will have a more profound and immediate impact on
industry dealing with materials such as aerospace, automobiles, coatings, construction,
cosmetics, ceramics, composites, agriculture, detergents, die moulding, drug
delivery, fertilizers, food, fuel production, lubricants, medical supplies, metals,
optical equipment, paint, paper, pharmaceuticals, polymers, power generation,
sensors, tools and textiles, to name but only a few industries that come to mind
immediately. The rapid pace at which nanotechnology is moving forward is
probably the main reason that it has come to the attention of almost every policy
maker and senior manager.

Although biotechnology has long been observed and supported, its full commercial
potential is expected to come to fruition only within the next 20 years or so. In
contrast to biotechnology, nanotechnology has already found its application in some
of the largest industries, such as the textile industry, due to the advantage of not
requiring the long clinical trials that are needed for any new biotechnology product.
Another major difference between biotechnology and nanotechnology is that
biotechnology focuses on a single main base material, i.e. genes and cells, while
engineering at the nanoscale is almost unlimited in its choice of base materials, may
it be mineral, plant, animal, human, or combinations of such. That, of course, raises
some brows. Consequently, nanotechnology has found an immediate spot on
agendas of policy makes and industry leaders.
Since 2001 an average of about 20–30% of national funding is matched by state (province) funding.Private funding (industry, venture capital) is estimated to be larger than government
funding except for the smaller Asian development countries. After an initial boost
by governments, funding for nanotechnology has steadily decreased over the past
years, which reflects both cautious national budgeting and the additional financial
input from private investment as the first R&D spin-offs and products are entering
the market.Interestingly, this general trend is not shared by Europe and
Asia (excluding Japan). In Europe, additional public investment in nanotechnology
is increasing at a staggering rate
Most of Asia is used to long-term national plans raging from 5 to 10 years, which
requires considerable planning ahead, including major infrastructure building.
China’s investment commitment for the five-year plan ending in 2005 is $280 million
for Korea’s ten-year plan ending in 2010 it is $2 billion; and it is $620 million for
Taiwan’s five-year plan ending in 2007. Malaysia allocated 9% ($23 million) of its
8th five-year plan to nanotechnology and precision engineering (Plan Intensification
of Priority Research Areas) ending 2008. Thailand is earmarking $25 million for
nanotechnology for the five-year period ending in 2008, and Japan will be investing
over $900 million each year over the next five years. Australia has identified
nanotechnology as one of its four funding areas of national priority.

Static Electricity,Non-electrical energy

Static Electricity
Charge carriers, particularly electrons, can build up, or become deficient, on things
without flowing anywhere. You’ve probably experienced this when walking on a carpeted
floor during the winter, or in a place where the humidity was very low. An excess
or shortage of electrons is created on and in your body. You acquire a charge of static
electricity. It’s called “static” because it doesn’t go anywhere. You don’t feel this until you
touch some metallic object that is connected to earth ground or to some large fixture;
but then there is a discharge, accompanied by a spark that might well startle you. It is
the current, during this discharge, that causes the sensation that might make you jump.
If you were to become much more charged, your hair would stand on end, because
every hair would repel every other. Like charges are caused either by an excess or a deficiency
of electrons; they repel. The spark might jump an inch, two inches, or even six
inches. Then it would more than startle you; you could get hurt. This doesn’t happen
with ordinary carpet and shoes, fortunately. But a device called a Van de Graaff generator,
found in some high school physics labs, can cause a spark this large

Non-electrical energy

In electricity and electronics, there are many kinds of phenomena that involve
other forms of energy besides electrical energy.
Visible light is an example. A light bulb converts electricity into radiant energy that
you can see. This was one of the major motivations for people like Thomas Edison to
work with electricity. Visible light can also be converted into electric current or voltage.
A photovoltaic cell does this.
Light bulbs always give off some heat, as well as visible light. Incandescent lamps
actually give off more energy as heat than as light. And you are certainly acquainted
with electric heaters, designed for the purpose of changing electricity into heat energy.
This “heat” is actually a form of radiant energy called infrared. It is similar to visible
light, except that the waves are longer and you can’t see them.
Electricity can be converted into other radiant-energy forms, such as radio waves,
ultraviolet, and X rays. This is done by things like radio transmitters, sunlamps, and
X-ray tubes.
Fast-moving protons, neutrons, electrons, and atomic nuclei are an important form
of energy, especially in deep space where they are known as cosmic radiation. The energy
from these particles is sometimes sufficient to split atoms apart. This effect makes
it possible to build an atomic reactor whose energy can be used to generate electricity.
Unfortunately, this form of energy, called nuclear energy, creates dangerous byproducts
that are hard to dispose of.
When a conductor is moved in a magnetic field, electric current flows in that
conductor. In this way, mechanical energy is converted into electricity. This is how a
generator works. Generators can also work backwards. Then you have a motor that
changes electricity into useful mechanical energy.
A magnetic field contains energy of a unique kind. The science of magnetism is
closely related to electricity. Magnetic phenomena are of great significance in electronics.
The oldest and most universal source of magnetism is the flux field surrounding the
earth, caused by alignment of iron atoms in the core of the planet.
A changing magnetic field creates a fluctuating electric field, and a fluctuating
electric field produces a changing magnetic field. This phenomenon, called electromagnetism,
makes it possible to send radio signals over long distances. The electric
and magnetic fields keep producing one another over and over again through space.
Chemical energy is converted into electricity in all dry cells, wet cells, and batteries.
Your car battery is an excellent example. The acid reacts with the metal electrodes
to generate an electromotive force. When the two poles of the batteries are
connected, current results. The chemical reaction continues, keeping the current
going for awhile. But the battery can only store a certain amount of chemical energy.
Then it “runs out of juice,” and the supply of chemical energy must be restored by
charging. Some cells and batteries, such as lead-acid car batteries, can be recharged
by driving current through them, and others, such as most flashlight and
transistor-radio batteries, cannot

Current

Current
Whenever there is movement of charge carriers in a substance, there is an electric
current. Current is measured in terms of the number of electrons or holes passing a
single point in one second.
Usually, a great many charge carriers go past any given point in one second, even if
the current is small. In a household electric circuit, a 100-watt light bulb draws a current
of about six quintillion (6 followed by 18 zeroes) charge carriers per second.
Even the smallest mini-bulb carries quadrillions (numbers followed by 15 zeroes) of
charge carriers every second. It is ridiculous to speak of a current in terms of charge
carriers per second, so usually it is measured in coulombs per second instead. A
coulomb is equal to approximately 6,240,000,000,000,000,000 electrons or holes. A current
of one coulomb per second is called an ampere, and this is the standard unit of
electric current. A 100-watt bulb in your desk lamp draws about one ampere of current.
When a current flows through a resistance—and this is always the case because
even the best conductors have resistance—heat is generated. Sometimes light and
other forms of energy are emitted as well. A light bulb is deliberately designed so that
the resistance causes visible light to be generated. Even the best incandescent lamp is
inefficient, creating more heat than light energy. Fluorescent lamps are better. They
produce more light for a given amount of current. Or, to put it another way, they need
less current to give off a certain amount of light.
Electric current flows very fast through any conductor, resistor, or semiconductor.
In fact, for most practical purposes you can consider the speed of current to be the
same as the speed of light: 186,000 miles per second. Actually, it is a little less.

Thursday, February 22, 2007

VAST VISTA: A choice of three consumer versions of Windows confronts buyers.

Bangalore: Three versions of Windows Vista confront buyers. That is not to say that PC owners — at last count there were about 50 million of them in India, 9 out of 10 being users of an earlier Windows version — know quite what to do now.
This is partly because Microsoft, while asking us to say `wow!' at all the new features, has been rather coy with practical details — like who must upgrade, who would be better off upgrading — and how much it is all going to cost.

Launch event
The main launch event in Mumbai was replete with Bollywood `masala' — but scant on earthy details such as how much each of the confusingly plentiful `avatars' of Vista will set us back in rupees.
Here's some help: There are three consumer versions of Vista that one can buy off the shelf — and a fourth called Starter Edition that is special to India: It will be only be sold pre-installed on entry-level PCs marketed here.
The three `shrink wrapped' versions range from the Home Basic, for those who browse the Net, write letters and e-mails — and do little else with their PC. If your PC has multimedia attachments that allow you to watch movies, play music and play graphics-rich games, the Home Premium version is for you (It corresponds roughly to what was called Windows XP Media Centre Edition).
For those who want to mix business and pleasure — the full suite of office functionality as well as infotainment features — there is Windows Vista Ultimate. But, you still need to separately install the latest version of the productivity suite, Microsoft Office 2007, to get most of the common business features.
Basic hardware
Microsoft says the basic hardware required is a modern chip (that is 800 MHz or faster); 512 MB of memory, 20 GB of hard disk and a graphics processor with what is called DirectX 9. This might just work for the Starter edition — but except allowing you to search both your desktop and the Internet with a click or two, it will miss out on most the features that take Vista beyond the old XP.
Our take: If so, why bother to upgrade? For the Premium and Ultimate versions, Microsoft recommends 1 GB of memory and a graphics card with at least 128 MB of its own memory. It also suggests at least 40 GB of hard disk. All three versions will take up about 15 GB of your disk space. After trying out the evaluation editions, we think users will need at least 2 GB of RAM to (as a famous petrol slogan of yesteryear went) ``fill up and feel the difference.''
The difference is mainly the much-touted Aero effect where 3D combined with a translucent `glass' effect has all your pages and open applications seeming to stand up in a see-through file on the screen. All versions boast of extremely user-friendly `parental controls' to monitor kids' surfing — and enhanced security features against junk mail (spam) and malicious mail — but it is too early to say how effective they are. And be warned: you still need to install a third party anti-virus software — unless you like to live dangerously.
Key question
Now the key question: Which Vista will work on your present PC? Microsoft has created a special download called Vista Upgrade Adviser at www.windowsvista.com, which examines your hardware and software and recommends what will work best for you. When I tried it on my AMD Athlon XP 2400-based PC currently running Windows XP, it suggested I could go in for Home Premium but it warned that my Xerox laser printer and Nero software for a Samsung Combo CD-DVD drive might not work. It has no issues with my HP deskjet printer.
Common peripherals
This is likely to happen with a lot of common peripherals. Our feedback is that the problem will bug many users for at least 6-8 months more since there are hardly any accessories or PC devices that include a Vista driver today.
So finally: Who should upgrade? If you are currently running a version older that XP — like Win 98 — then you have no choice since you are stuck with a `dead' version: You might as well change to one of the new Vista versions. If you are buying a new PC or laptop, it is good to insist on getting a Vista flavour pre installed. This will probably be cheaper than buying one separately since the shop shelf cost is likely to be Rs. 6000 to Rs. 10,000 at least (this is our market perception; Microsoft is not saying). If you are a Windows XP user you might like to change to Vista — if you must have the undoubtedly strong safety and search features. Or you might like to `wait and watch' till the compatibility issues are sorted out.

An Introduction To Black Holes, Information And The String Theory Revolution

An Introduction To Black Holes, Information And The String Theory Revolution: The Holographic Universe Paperback: 200 pages Publisher: World Scientific Publishing Company (December 31, 2004) Language: English ISBN-10: 9812561315



http://rapidshare.com/files/17418019/Black_Holes.rar

How to perform disk error checking in Windows XP

To run Chkdsk at the command prompt
1.
Click Start, and then Run.
2.
In Open, type cmd, and then press ENTER.
3.
Use one of the following procedures:

To run Chkdsk in read-only mode, at the command prompt, type chkdsk, and then press ENTER.

To repair errors without scanning the volume for bad sectors, at the command prompt, type chkdsk volume:/f, and then press ENTER.Note If one or more of the files on the hard disk drive are open, you will receive the following message:
Chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts? (Y/N)Type Y, and then press ENTER to schedule the disk check, and then restart your computer to start the disk check.

To repair errors, locate bad sectors, and recover readable information, at the command prompt, type chkdsk volume:/r, and then press ENTER Note If one or more of the files on the hard disk drive are open, you will receive the following message:
Chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts? (Y/N)Type Y, and then press ENTER to schedule the disk check, and then restart your computer to start the disk check.

To run Chkdsk from My Computer or Windows Explorer
1.
Double-click My Computer, and then right-click the hard disk drive that you want to check.
2.
Click Properties, and then click Tools.
3.
Under Error-checking, click Check Now. A dialog box that shows the Check disk options is displayed,
4.
Use one of the following procedures:

To run Chkdsk in read-only mode, click Start.

To repair errors without scanning the volume for bad sectors, select the Automatically fix file system errors check box, and then click Start.

To repair errors, locate bad sectors, and recover readable information, select the Scan for and attempt recovery of bad sectors check box, and then click Start.
Note If one or more of the files on the hard disk drive are open, you will receive the following message:
The disk check could not be performed because the disk check utility needs exclusive access to some Windows files on the disk. These files can be accessed by restarting Windows. Do you want to schedule the disk check to occur the next time you restart the computer?Click Yes to schedule the disk check, and then restart your computer to start the disk check.

Sunday, February 18, 2007

Basic Electronics - Conductors,Insulators,Resistors and Semiconductors





Conductors


In some materials, electrons move easily from atom to atom. In others, the electrons
move with difficulty. And in some materials, it is almost impossible to get them to move.
An electrical conductor is a substance in which the electrons are mobile.
The best conductor at room temperature is pure elemental silver. Copper and aluminum
are also excellent electrical conductors. Iron, steel, and various other metals are
fair to good conductors of electricity.
In most electrical circuits and systems, copper or aluminum wire is used. Silver is
impractical because of its high cost.
Some liquids are good electrical conductors. Mercury is one example. Salt water is
a fair conductor.
Gases are, in general, poor conductors of electricity. This is because the atoms or
molecules are usually too far apart to allow a free exchange of electrons. But if a gas becomes
ionized, it is a fair conductor of electricity.
Electrons in a conductor do not move in a steady stream, like molecules of water
through a garden hose. Instead, they are passed from one atom to another right next to
it.This happens to countless atoms all the time. As a result, literally trillions
of electrons pass a given point each second in a typical electrical circuit.
You might imagine a long line of people, each one constantly passing a ball to the
neighbor on the right. If there are plenty of balls all along the line, and if everyone keeps
passing balls along as they come, the result will be a steady stream of balls moving along
the line. This represents a good conductor.
If the people become tired or lazy, and do not feel much like passing the balls along,
the rate of flow will decrease. The conductor is no longer very good.





Insulators
If the people refuse to pass balls along the line in the previous example, the line represents
an electrical insulator. Such substances prevent electrical currents from flowing,
except possibly in very small amounts.
Most gases are good electrical insulators. Glass, dry wood, paper, and plastics are
other examples. Pure water is a good electrical insulator, although it conducts some
current with even the slightest impurity. Metal oxides can be good insulators, even
though the metal in pure form is a good conductor.
Electrical insulators can be forced to carry current. Ionization(
Ions
If an atom has more or less electrons than neutrons, that atom acquires an electrical
charge. A shortage of electrons results in positive charge; an excess of electrons gives a
negative charge. The element’s identity remains the same, no matter how great the excess
or shortage of electrons. In the extreme case, all the electrons might be removed
from an atom, leaving only the nucleus. However it would still represent the same
element as it would if it had all its electrons.
A charged atom is called an ion. When a substance contains many ions, the material
is said to be ionized.) can take place;




when electrons are stripped away from their atoms, they have no choice but to move along.
Sometimes an insulating material gets charred, or melts down, or gets perforated by a
spark. Then its insulating properties are lost, and some electrons flow.
An insulating material is sometimes called a dielectric. This term arises from the
fact that it keeps electrical charges apart, preventing the flow of electrons that would
equalize a charge difference between two places. Excellent insulating materials can be
used to advantage in certain electrical components such as capacitors, where it is important
that electrons not flow.
Porcelain or glass can be used in electrical systems to keep short circuits from occurring.
These devices, called insulators, come in various shapes and sizes for different
applications. You can see them on high-voltage utility poles and towers. They hold the
wire up without running the risk of a short circuit with the tower or a slow discharge
through a wet wooden pole.





Resistors
Some substances, such as carbon, conduct electricity fairly well but not really well. The
conductivity can be changed by adding impurities like clay to a carbon paste, or by winding
a thin wire into a coil. Electrical components made in this way are called resistors. They
are important in electronic circuits because they allow for the control of current flow.
Resistors can be manufactured to have exact characteristics. Imagine telling each
person in the line that they must pass a certain number of balls per minute. This is analogous
to creating a resistor with a certain value of electrical resistance.
The better a resistor conducts, the lower its resistance; the worse it conducts, the
higher the resistance.Electrical resistance is measured in units called ohms. The higher the value in ohms, the greater the resistance, and the more difficult it becomes for current to flow.
For wires, the resistance is sometimes specified in terms of ohms per foot or ohms per
kilometer. In an electrical system, it is usually desirable to have as low a resistance, or
ohmic value, as possible. This is because resistance converts electrical energy into heat.
Thick wires and high voltages reduce this resistance loss in long-distance electrical
lines. This is why such gigantic towers, with dangerous voltages, are necessary in large
utility systems.





Semiconductors









In a semiconductor, electrons flow, but not as well as they do in a conductor. You might
imagine the people in the line being lazy and not too eager to pass the balls along. Some
semiconductors carry electrons almost as well as good electrical conductors like copper
or aluminum; others are almost as bad as insulating materials. The people might be just
a little sluggish, or they might be almost asleep.
Semiconductors are not exactly the same as resistors. In a semiconductor, the material
is treated so that it has very special properties.
The semiconductors include certain substances, such as silicon, selenium, or gallium,
that have been “doped” by the addition of impurities like indium or antimony.
Perhaps you have heard of such things as gallium arsenide, metal oxides, or silicon
rectifiers. Electrical conduction in these materials is always a result of the motion
of electrons. However, this can be a quite peculiar movement, and sometimes engineers
speak of the movement of holes rather than electrons. A hole is a shortage of an
electron—you might think of it as a positive ion—and it moves along in a direction
opposite to the flow of electrons


Note:Holes move in the opposite direction from electrons in a semiconducting material



When most of the charge carriers are electrons, the semiconductor is called
N-type, because electrons are negatively charged. When most of the charge carriers are
holes, the semiconducting material is known as P-type because holes have a positive
electric charge. But P-type material does pass some electrons, and N-type material carries
some holes. In a semiconductor, the more abundant type of charge carrier is called
the majority carrier. The less abundant kind is known as the minority carrier.
Semiconductors are used in diodes, transistors, and integrated circuits in almost
limitless variety. These substances are what make it possible for you to have a computer
in a briefcase. That notebook computer, if it used vacuum tubes, would occupy a skyscraper,
because it has billions of electronic components. It would also need its own
power plant, and would cost thousands of dollars in electric bills every day. But the circuits
are etched microscopically onto semiconducting wafers, greatly reducing the size
and power requirements.


Multimeter - Learn Electronics and Electrical


In the electronics lab, a common piece of test equipment is the multimeter, in which
different kinds of meters are combined into a single unit. The volt-ohm-milliammeter
(VOM) is the most often used. As its name implies, it combines voltage, resistance and
current measuring capabilities.
You should not have too much trouble envisioning how a single milliammeter can be
used for measuring voltage, current and resistance. The preceding discussions for measurements
of these quantities have all included methods in which a current meter can
be used to measure the intended quantity.
Commercially available multimeters have certain limits in the values they can measure.
The maximum voltage is around 1000 V; larger voltages require special leads and
heavily insulated wires, as well as other safety precautions. The maximum current
that a common VOM can measure is about 1 A. The maximum resistance is on the order
of several megohms or tens of megohms. The lower limit of resistance indication is
about an ohm.

Kamal Hassan


Ever since Kamal hassan burst on the scene as a
Precocious child,the cinematic world knew that a
Talent both rare and exceptional was upon it.One
Of the then great actors recalled that many of his
Directors had once told him the little man had a
‘gift from above’,Great things were foretold then,
and his 50 years old career has been an inexorable
journey towards acting immortality.So when he had
the record for acquiring the maximum number of Nati-
nal awards,no one was surprised,In this lack of su-
rprise lies the nub of Hassan’s greatness.
In an era of the hyperbole,’greatness’ – conferred upon too
many too easily – has lost its meaning.Many a you-
ng talent has been spotted in the cinema’s rich hist-
ory and nailed to the cross of greatness.But no one
has fulfilled every prediction,however seemingly fa-
ntastic,and constantly forced others to rethink their
perceptions and definitions of greatness as Hassan
has.His first movie was a baptism of fire .when
he acted on despite no experience his crew saw the f-
irst portents of greatness.
On acquiring his first national award, Hassan spoke of the discipline he has needed in life. It's an aspect that is often forgotten during talk of his special ability. Top-flight acting is a jealous spirit, demanding single-point focus and total devotion. The path to success is beset with pitfalls that test character and spirit. There are few sadder sights in cinema than a talent squandered either for want of desire or an inability to remain grounded in reality — the mercurial footballer George Best, who left us, was one such. Hassan's successes on the field have also been a function of how well he has managed them off it.
Those who posit a genius with flaws as being more romantic choose to ignore the sacrifices that total commitment entails; the denial of romance and flair, however, is just as piquant. The man from paramakudi has been able to marry his amazing zest for cinema with the rigour essential for the pursuit of acting Nirvana. Through it all, he has carried the expectations of millions with grace and humility. The 50-years-old has transcended limits that shackle and stereotype a cinema celebrity. He is an icon, representative of a new, vibrant India and intensely proud of his Indianness.if hassan’s legacy has already been scripted,then its only because he has
acted it out to Perfection.

Free ebooks,rapidshare,great blog,megaupload,frantic ramblings,ideas,home equity loans,learn electronics,download
Powered By Blogger