Aerogel

A MIRACLE material for the 21st century could protect your home against bomb blasts, mop up oil spillages and even help man to fly to Mars.
Aerogel, one of the world’s lightest and expensive solids, can withstand a direct blast of 1kg of dynamite and protect against heat from a blowtorch at more than 1,300C. It has the lowest density of any product known to man, yet at the same time it can do so much. Although aerogel is classed as a solid, 99% of the substance is made up of gas, which gives it a cloudy appearance.
Aerogel is nicknamed "frozen smoke" and is made by extracting water from a silica gel, then replacing it with gas such as carbon dioxide. The result is a substance that is capable of insulating against extreme temperatures and of absorbing pollutants such as crude oil. For those of you who have always wanted to touch an aerogel, it feels like styrofoam. Silica aerogel is transparent with a blue color.

Aerogel was first created by Steven Kistler in 1931, as a result of a bet with Charles Learned over who could replace the liquid inside a jam(jelly) jar with gas without causing shrinkage, but early versions were so brittle and costly that it was largely consigned to laboratories.

It was not until a decade ago that Nasa started taking an interest in the substance and putting it to a more practical use. In 2002 Aspen Aerogel, a company created by Nasa, produced a stronger and more flexible version of the gel. It is now being used to develop an insulated lining in space suits for the first manned mission to Mars, scheduled for 2018. Aerogel is also being tested for future bombproof housing and armour for military vehicles. In the laboratory, a metal plate coated in 6mm of aerogel was left almost unscathed by a direct dynamite blast.



In the picture, you can see a 2 gm of aerogel easily holding a brick of 2.5 kgs.

How is Aerogel Made?
Aerogel starts out as a gel, called alcogel. Alcogels are made by polymerizing a silicon alkoxide with water in a mixing solvent (such as ethanol). The reaction occurs by hydrolysis and water condensation, joining together the alkoxide molecules making silicon-oxygen bonds to form oligomers (mini-polymers). The oligomers join together and form one giant molecule, which is the solid part of a gel. The silica matrix in the alcogel is filled with ethanol, having tiny little pockets 5 to 150 nanometers across. These tiny pockets of ethanol in the gel are called nanopores.
Aerogel is made by drying the alcogel and extracting the liquid from the solid silica component. Instead of evaporating the solvent, the gel can be supercrtically dried. Supercritical drying is a process in which liquid can be removed from a gel without causing the gel to collapse. Supercritically drying alcogel is a way for the liquid in the gel to slowly sneak out of the solid silica matrix without causing the silica matrix to collapse from capillary action. This is done by heating the gel past its solvent's critical point. Once the liquid has snuck out of the gel, the solvent can be vented off as a gas. The remaining solid is made of silica, with tiny pockets (nanopores) filled with air, and is 50-99% of the volume of the original alcogel. This solid is called an aerogel.

why is aerogel blue?
The same reason the sky is blue--Rayleigh scattering or Raman Effect.

Rayleigh scattering is an optical phenomenon that results when white light scatters off of particles smaller than the wavelengths of light, particles typically of the size 5 to 200 nm. These particles scatter the shorter wavelengths of white light more easily than the longer wavelengths, meaning that blue and violet are scattered the most. Our eyes are much more sensitive to blue wavelengths than to violet wavelengths, and so we only see blue light. Aerogels contain nanopores of air that are only a few hundred times larger than atoms. These nanopores, made of silica (which is what glass is made out of) act as particles that scatter white light and make the aerogel appear blue.

Isn't it a great invention of this century, the best part is it can be used to save the mankind by providng blastproof house, on the contrary the worst part is it is very expensive material on the earth.

Hope you had enjoyed getting this gyan, i know part of it is too technical, but thats easy to understand as well.

Super Computers

Hi,

I was taken by surprise on knowing the facts of IBMs role and development is the area of Super Computers. Then, I thought why not surprise you all by these facts. Hope the following article about super computer sounds equally interesting for you too.

IBM has won a $290m US government contract to build what are expected to be the world's two fastest supercomputers at Lawrence Livermore National Laboratory.
One machine, ASCI Purple for nuclear weapons research, will be three times faster than the world's current top-ranked supercomputer, NEC's Earth Simulator, which has been clocked at 35 trillion calculations per second, or "teraflops." The other machine, the Linux-powered Blue Gene/L for civilian research, will be 10 times faster than Earth Simulator with a speed of 360 teraflops, according to IBM.
In 1993, IBM got its first systems onto the Top500 list of the world's fastest supercomputers. Today, the list includes 134 IBM machines.
The design details of Blue Gene/L still haven't been settled beyond a plan for it to have 65,636 computing nodes. The design for ASCI Purple, though, is better established, and brute force figures prominently in it.
ASCI Purple, is expected to have 196 interconnected 64-processor servers, making a total of 12,544 Power5 chips. It will come with 50 terabytes of memory -- about 20,000 times as much as a PC. The supercomputer also will have IBM disk storage arrays holding 2 petabytes, or a quadrillion bytes, of data -- about 50,000 times the capacity of a PC.
As for physical size, ASCI Purple will weigh about 197 tons, be linked to 119 miles of optical cable and 28 miles of copper cable, and occupy 8,900 square feet of floor space -- or about two basketball courts. It will consume 4.7 megawatts of power, enough current for 4,000 homes, according to IBM.
Supercomputers don't sell in as large volumes as mainstream business systems, but the market is important for other reasons. First, supercomputer research and development can be plowed back into mainstream computer products. In addition, government-funded initiatives help subsidise that development work. For example, the US Energy Department's Advanced Simulation and Computing programme, which grew out of the earlier Accelerated Strategic Computing Initiative, is underwriting ASCI Purple.
Blue Gene/L is one step in IBM's ongoing project to build a machine by 2007 that can perform a quadrillion calculations per second -- a "petaflop". The task of the ultimate Blue Gene computer will be to predict the folding of proteins, the large biological molecules that are assembled from genetic information encoded in DNA.
The 360-teraflop performance of Blue Gene/L is expected to be more than the collective 293-teraflop ability of today's entire Top500 supercomputer list.
For enormous systems with thousands of processors, a major challenge will be simply keeping all the components up and running and circumventing problem areas when they occur. IBM is working on autonomic computing technology, or machines that can diagnose and repair problems themselves, so we can make systems of this size more self-maintaining. If there are failures, they can be routed around so the machine is still available to users.
In the mid-1990s, the Energy Department launched what was then the Accelerated Strategic Computing Initiative, a plan to spur the development of supercomputers so they'd be fast enough to simulate nuclear weapons explosions in detail. The program, with a budget in the billions of dollars, was embraced by the nation's three national laboratories -- Sandia National Laboratories, Los Alamos National Laboratory and Lawrence Livermore National Laboratory -- as a way they could assure that nuclear weapons would work as designed, without having to rely on actual tests.
The result has been a succession of ever-more-powerful supercomputers. The first contract was awarded in 1995 for work at the Sandia labs in Albuquerque, N.M., on Intel's ASCI Red system. The supercomputer was designed to perform 1 trillion calculations per second, or 1 teraflop.
Next came the three-teraflop machines, Blue Mountain, built by SGI for Los Alamos National Laboratory in New Mexico, and Blue Pacific, built by IBM at the Livermore lab in California.
The third generation was ASCI White, the second IBM machine at Livermore labs. It was designed to run at 10 teraflops, but the machine topped out at 12.3 teraflops. The fourth generation, ASCI Q at Los Alamos, is designed ultimately to reach 30 teraflops. However, it's still under construction and so far exists as two 7.7-teraflop parts.
ASCI Purple -- named after the colour resulting from a mixture of red, white, and blue -- was to be the pinnacle of the programme, with a target of 100 teraflops. It was to be the system that could handle the ultimate task: a "full physics" simulation in three dimensions of a nuclear blast, both of the "primary" fission explosion that begins the process and the resulting "secondary" fusion reaction that provides most of the energy in the nuclear detonation.
But IBM believes there will be successors to ASCI Purple. ASCI was originally laid out through 100 teraflops. But clearly they have a lot more science that needs to be done within the programme. So, believe they have further aspirations.
Lab researchers are looking forward to more-sophisticated modelling abilities from future supercomputers. The primary and secondary of a simplified theoretical weapon is simulated. The simulation took about two months, but ASCI Purple will allow simulations in less time than that.
Americas dominates the supercomputing scene with 294 Super Computers followed by Europe (114), and Asia (81). In terms of countries, USA enjoys a dominant position with 255 installations, followed by Germany (40), UK (32), Japan (23), China (19), South Korea (14), France (11), and India (8).
In India, C-DAC had managed to enter the Super 500 Club in 2003 with its Param Padma Super Computer (Rank 171). Institute of Mathematical Sciences at Chennai had an entry (Rank 253) in the 2004 edition; unfortunately both have fallen out of this list in 2005.
Delhi area (ONGC (3) & Institute of Genomics) and Bangalore (Intel India (2) and Tech Pacific & PCS Trading) are the concentrations of super computing in India.
PARAM - India's reply to Super Computer
PARAM is a series of supercomputers developed by the Centre for Development of Advanced Computing (C-DAC) in Pune, India. The latest machine in the series is the PARAM Padma, which reached no. 171 on the TOP500 in 2003. Others include PARAM 10000 and PARAM 9000/SS. The PARAM 10000 was India's first TFLOPS computer.

The success of PARAM can be seen as a great example as how restrictions of scientific knowledge turned out to be a blessing in disguise. The USA's supercomputing hardware embargo of India in the early 80s forced the Indian scientists to independently develop the components required for PARAM. The various components used in the PARAM series were Sun UltraSPARC II, later IBM POWER 4 processors , Ethernet , and AIX Operating System.

C-DAC has also developed a high performance System Area Network called the PARAMNet-II having transfer speeds of up to 2.5 Gbit/s and latencies as low as 10 microseconds. The major applications of PARAM 10000 are in long-range weather forecasting, remote sensing, drug design and molecular modelling. PARAMs in the future may well be used for India's space programme. Plans to use it for oil and gas exploration are also on the line.

Hardware Resources:
Configuration : 54 Nos. of 4-Way SMP nodes and 1 No. of 32-Way SMP node.
No. of Processors : 248 (Power 4@1GHz).
Aggregate Memory : 0.5 TeraBytes (@ 8GB per node and 64GB per large SMP node).
Internal Storage : 4.5 TeraBytes (@ 72GB per node and 576GB per large SMP node).
Operating System : AIX 5L .
Aggregate Peak Computing Power : 1005 GFs (~1 TF).
While the PARAM represents a major technological leap in India, its performance pales in comparison to supercomputers from China, US and Japan.
China unveiled the Dawning 4000L, a machine which offers 3 teraflops of computing power for scientific and other types of information processing. It houses 644 Intel processors, 644GB of memory and 100 terabytes of storage. High-performance computers from Japanese and US-based companies boast of even more impressive hardware arsenals. NEC's Earth Simulator supercomputer consists of over 5,200 processors and 40 teraflops of power. IBM's upcoming Blue Gene supercomputers will boast 65,000 processors.

There are Indian hands behind the toppers in the Top 500; India-born BJ Arun founded California Data Corporation with rank 7 and India-born Professor Srinidhi Varadarajan assembled Apple cluster at Virginia Tech at rank 14 does Indians proud; when will India catch up?

Thank you for your precious time allocation.
Have a nice week-end ahead.

Eiffel Tower

Hi,

Recently, i came accross an interesting article about Eiffel tower, i know many of us know these facts, but still wanted to refresh (y)our information about Eiffel Tower.

Location
Paris, France
Completed Construction by 1889

Use
Observation tower
Radio broadcasting tower
Advertising space

Height
Antenna/Spire 324 m (1063 ft)

Roof
300.65 m (986 ft)

Architect
Gustave Eiffel

The Eiffel Tower (French: La Tour Eiffel) is an iron tower built on the Champ de Mars beside the River Seine in Paris, France. It is the tallest structure in Paris and possibly the most recognized monument in Europe. Named after its designer, engineer Gustave Eiffel, it is the most visited monument in the world; 6,428,441 people visited the tower in 2005 and more than 200,000,000 since its construction. Including the 24 m (78.7 ft) antenna, the structure is 324 m (1063 ft) high (since 2000), which is about 81 stories. In 1902, it was struck by lightning, which meant that 300 feet of the top had to be reconstructed and the lights illuminating the tower had to be replaced, as they were damaged by the high energy of the lightning.
At the time of its construction in 1887, the tower replaced the Washington Monument as the world's tallest structure, a title it retained until 1930, when New York City's Chrysler Building (319 m/1046.58 ft tall) was completed (today, the Eiffel Tower is taller than the Chrysler Building). The tower is now the fifth-tallest structure in France. The Eiffel Tower is the tallest structure in Paris, with the second-tallest being the Tour Montparnasse (210 m/689 ft) and it will soon be the Tour AXA (225.11 m/738.5 ft).
The structure of the Eiffel Tower weighs 7300 tons. There are 1660 steps (360 to the first level, another 359 to the second). It is not possible for the public to reach the summit via the stairs, lifts are required beyond the second platform. Lift tickets may be purchased at the base or either platform. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18cm, due to thermal expansion of the metal on the side facing the sun. The tower also sways 6-7cm in the wind.
Maintenance of the tower includes applying 50/60 tons of three graded tones of paint every seven years to protect it from rust. On occasion, the color of the paint is changed — the tower is currently painted a shade of brownish-gray. However, the tower is actually painted three different colors in order to make it look the same color. The colors change from dark to light from top to bottom, but it looks the same because of the background (the sky being light and the ground being dark). On the first floor, there are interactive consoles hosting a poll for the color to use for a future session of painting. The co-architects of the Eiffel Tower are Emile Naugier, Maurice Koechlin and Stephen Sauvestre.

The structure was built between 1887 and 1889 as the entrance arch for the Exposition Universelle, a World's Fair marking the centennial celebration of the French Revolution. Eiffel originally planned to build it in Canada, for the Universal Exposition of 1888, but they rejected it. The tower was inaugurated on 31 March 1889, and opened on 6 May. Three hundred workers joined together 18,038 pieces of puddled iron (a very pure form of structural iron), using two and a half million rivets, in a structural design by Maurice Koechlin. The risk of accident was great, for unlike modern skyscrapers the tower is an open frame without any intermediate floors except the two platforms. Yet because Eiffel took safety precautions including use of movable stagings, guard-rails and screens, only one man died.

The shape of the tower was determined by mathematical calculation involving wind resistance. Several theories of this mathematical calculation have been proposed over the years, the most recent is a nonlinear integral differential equation based on counterbalancing the wind pressure on any point on the tower with the tension between the construction elements at that point. That shape is exponential.[10][11]

Here are the ticket rates:

Elevator

Full rate Reduced rate
(Adults/Children +12) (Children 3-11)
1st floor 4.50 € 2.30 €
2nd floor 7.80 € 4.30 €
Top 11.50 € 6.30 €

Stairs
(+25 years old) (- 25 years old)
1st & 2nd floors 4.00 € 3.10 €

Children under 3 are free guests at the Eiffel Tower.

Hope you enjoyed having the information on Eiffel tower.

Welcome Note

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