Sepientia » General Science

New way of producing electricity

admin — Mon, 08 Mar 2010 22:27:11 +0000

A team of scientists at MIT has discovered a previously unknown phenomenon that can cause powerful waves of energy to shoot through minuscule wires known as carbon nanotubes, a discovery that could lead to a new way of producing electricity.

The phenomenon, described as thermopower waves, “opens up a new area of energy research, which is rare,” said Michael Strano, MIT’s Charles and Hilda Roddey Associate Professor of Chemical Engineering, who was the senior author of a paper describing the new findings.

Like a collection of flotsam propelled along the surface by waves traveling across the ocean, it turns out that a thermal wave — a moving pulse of heat — traveling along a microscopic wire can drive electrons along, creating an electrical current. The key ingredient in the recipe is carbon nanotubes — submicroscopic hollow tubes made of a chicken-wire-like lattice of carbon atoms.

In the new experiments, each of these electrically and thermally conductive nanotubes was coated with a layer of a highly reactive fuel that can produce heat by decomposing.

This fuel was then ignited at one end of the nanotube using either a laser beam or a high-voltage spark, and the result was a fast-moving thermal wave travelling along the length of the carbon nanotube like a flame speeding along the length of a lit fuse.

According to Strano, in the group’s initial experiments, when they wired up the carbon nanotubes with their fuel coating in order to study the reaction, “lo and behold, we were really surprised by the size of the resulting voltage peak” that propagated along the wire.

After further development, the system now puts out energy, in proportion to its weight, about 100 times greater than an equivalent weight of lithium-ion battery.

While many semiconductor materials can produce an electric potential when heated, through something called the Seebeck effect, that effect is very weak in carbon.

“There’s something else happening here. We call it electron entrainment since part of the current appears to scale with wave velocity,” Strano said.

The thermal wave appears to be entraining the electrical charge carriers (either electrons or electron holes) just as an ocean wave can pick up and carry a collection of debris along the surface, he explained.

“This important property is responsible for the high power produced by the system,” Strano said.

Strano suggests that one possible application would be in enabling new kinds of ultra-small electronic devices.

Or it could lead to “environmental sensors that could be scattered like dust in the air,” he said.

ANI

Athanasius Kircher VS Leonardo da Vinci

admin — Fri, 19 Feb 2010 22:04:56 +0000

This traditional portrait of Athanasius Kircher gives his age as 76. The engraver has emphasized the energy in Kircher’s inquiring eyes. A professor of eloquence in Rome added the flowery inscription: “The painter or poet would declare only in error: ‘This is the man.’ But the farthest Antipodes know his name and face.”

Above, a detail from a page in Athanasius Kircher’s “Musurgia Universalis,” printed in 1650. A large part of the book is devoted to the history of instrumentation, including the anatomy of voice and hearing, and an extensive theory on acoustics entitled ‘Magia Phonocamptica, sive de Echo’, in which he described sound as ‘the ape of light.’

Invented device for the deaf and a megaphone. Described the phosphorescence and fluorescence. Designed magnetic watch.

Made some music of hydraulic machines. Has constructed the prototype of the synthesizer, which it was possible to obtain different timbres of wind, string instruments and noise, as well as programmed melodies within the scale tool.

The first used a microscope to examine the blood of patients with plague, and came to the conclusion that the disease is caused by microorganisms. He also suggested that effective measures to combat the disease – isolation, quarantine, burning clothes and diseased wearing protective masks.

Descended into the crater of the volcano Etna on Sicily. Created the theory of volcanism and water circulation within the body of the Earth.

Invented the world’s first projector, and includes a light source, and a slide, and an optical system, and the screen .

To study the ancient Egyptian hieroglyphs taught Syriac, Chaldean, Arabic and Coptic.

In fact, opened for Christian Kabbalah – presenting an image kabbalah sefirot of the tree is in the form in which it would be accessible and understandable to Christian readers.

Released the “Illustrated Encyclopedia of the Chinese Empire,” which summarized all the information known about China – Kircher was in correspondence with more than 760 scientists.

Created the “machine metaphor”.

Calculated that if the Tower of Babel reach the sky, she would have turned the Earth. Calculated the size of Noah’s Ark .

During the 30-year war against the Protestants fled first to Avignon, and then to Rome. Has published 40 books: arithmetic, geometry, trigonometry, algebra, the theory of logarithms, Astronomy, Chronograph, geography, acoustics, and anaclastics catoptrics, mechanics, statics, hydrology, hydraulic engineering, pyrotechnics, cryptography, fortification, topography, chemistry, architecture, construction mechanics , music, telescopes, microscopes, magnets and their properties, fluid bodies, machines, pneumatic machines, diving bells, military tactics and strategy, and so on.

The Future – Electric Cars

admin — Sun, 07 Feb 2010 21:06:57 +0000

The green brigade has precisely touched most of the industries; Automobile can be left as the fuel consumption is the highest in this sector. Efforts have been made in the past to promote electric cars but the end result has not been impressive to many. Electronic cars launched previously had few draw backs like their top speed not exceeding 20 miles per hour, long recharge hours, expensive and two seating capacity. Though they make no noise and are pollution free vehicles it didn’t made any difference.

A lot of time and money has been put in developing these electric cars and make them more lucrative to the buyer.

UK is coming up with a Electric car which will be a four seater, can run up to 70 miles without bothering to be recharged. It’s a Citroen C1 based car, which is joint venture by Peugeot, Toyota and Citroen. It shall take only six to seven hours to charge and can be charged in a 13a normal socket. Subsidies are also being discussed with British government to encourage people to go in for a Citroen C1. By 2011 Citroen C1will hit the market.

Up till now the designs of any of the previous launched electric cars have not tempted most of them to buy one. They are expensive no fancy features or designs and they could not accommodate large families either. Hope fully the scenario will change in the near future.

Another such product, which is with an electric motor running on three wheels, is an Aptera. It’s quite pleasing to eyes and pollution free.

Aptera 2e is originally manufactured in California, USA. Mostly to be launched by the end of 2009. Aptera 2e can run 100 miles without bothering to be recharged. This is a two seater car with comfortable space for luggage. A Navigation system, an air conditioner, Side and front airbags, Power locks and electric windows are few features of the Aptera2. You can go 0 to 60 in less than 10 seconds which is commendable for an electric car. Such features are not present in any of its present counterparts. You can plug it in to any normal outlet of about 110v which will be cost you about 50c. A test drive of the Aptera 2e shall be an experience you had been waiting for.

Aptera 2e will be launched in California initially then Florida followed by Texas. Only by 2010 or2011 it will be available in other parts of the US. With all the state of art facilities, saving a lot of your hard earned money on fuel and being an eco friendly vehicle it will surely be a treat to drive.

Our future lies in these cars. They only do well to the environment and also to your pockets. You might feel it on an expensive side initially but the amount of money you shall be saving on fuel in the long run is remarkable.

[ source ]

Tests of atomic bombs

admin — Thu, 24 Sep 2009 15:51:19 +0000

Robert Oppenheimer – father of the American atomic bomb, the head of the Manhattan Project.

Military generals and Robert Oppenheimer inspect the ruins of the tower after the first test of the atomic bomb on July 16 1945.

July 1946 – the atomic bomb at Bikini Atoll in the Pacific Ocean.

Atmospheric testing of nuclear weapons at Bikini Atoll

Atomic cake, which is cut by Vice Admiral William HP Blandy, his wife and Rear Admiral Frank Dzh.Louri at a reception in honor of successful tests.

Observers from the number of senior military commanders in the special glasses to watch the atomic explosion in 1951.

Nevada

Tests hydrogen bomb in 1952

President Jacques Chirac after the nuclear tests at Mururoa Atoll.

Scientists find evidence of hydrocarbons in Earth’s upper mantle

admin — Sat, 01 Aug 2009 13:31:29 +0000

In a new research, scientists have found for the first time that ethane and heavier hydrocarbons can be synthesised under the pressure-temperature conditions of the upper mantle of the Earth.

The research was conducted by scientists at the Carnegie Institution’s Geophysical Laboratory, with colleagues from Russia and Sweden.

Methane (CH4) is the main constituent of natural gas, while ethane (C2H6) is used as a petrochemical feedstock.

Both of these hydrocarbons, and others associated with fuel, are called saturated hydrocarbons because they have simple, single bonds and are saturated with hydrogen.

Using a diamond anvil cell and a laser heat source, the scientists first subjected methane to pressures exceeding 20 thousand times the atmospheric pressure at sea level and temperatures ranging from 1,300 Fahrenheit to over 2,240 Fahrenheit.

These conditions mimic those found 40 to 95 miles deep inside the Earth. The methane reacted and formed ethane, propane, butane, molecular hydrogen, and graphite.

The scientists then subjected ethane to the same conditions and it produced methane. The transformations suggest heavier hydrocarbons could exist deep down.

The reversibility implies that the synthesis of saturated hydrocarbons is thermodynamically controlled and does not require organic matter.

The scientists ruled out the possibility that catalysts used as part of the experimental apparatus were at work, but they acknowledge that catalysts could be involved in the deep Earth with its mix of compounds.

“We were intrigued by previous experiments and theoretical predictions,” said Carnegie’s Alexander Goncharov, a co-author.

“Experiments reported some years ago subjected methane to high pressures and temperatures and found that heavier hydrocarbons formed from methane under very similar pressure and temperature conditions,” he said.

“However, the molecules could not be identified and a distribution was likely. We overcame this problem with our improved laser-heating technique where we could cook larger volumes more uniformly. And we found that methane can be produced from ethane,” he added.

According to Professor Kutcherov, a coauthor, “The notion that hydrocarbons generated in the mantle migrate into the Earth’s crust and contribute to oil-and-gas reservoirs was promoted in Russia and Ukraine many years ago.”

“The synthesis and stability of the compounds studied here as well as heavier hydrocarbons over the full range of conditions within the Earth’s mantle now need to be explored,” he said.

source: ANI

First Hybrid Solar Power Station

admin — Sat, 25 Jul 2009 14:10:32 +0000

AORA, a leading Israeli solar energy technology company, launched world’s first hybrid solar thermal power station at Kibbutz Samar in southern Israel.

This marked the first time that concentrating solar power (CSP) stations can provide environmentally-friendly power 24 hours a day, according to AORA’s CEO, Haim Fried.

AORA’s “Power Flower” station, named due to its unique yellow tulip design, consists of a field of 30 tracking mirrors (heliostats) situated on half an acre of land.

Each of the station’s 30 heliostats tracks the sun and reflects its rays towards the top of a 30 meter-high tower housing a special solar receiver along with a 100 kilowatt gas turbine.

The patented receiver uses the solar energy to heat air to a temperature of 1,000 degrees Celsius and directs this energy into the turbine, which converts the thermal energy into electric power that will be fed directly into the national grid.

Besides solar energy, the power station can also run on other alternative fuel, including bio-gas, bio-diesel and natural gas. So the station can produce electricity when sunlight is insufficient, such as at night or when it is cloudy.

source: http://english.sina.com/

Scientists found mysterious forms of water

admin — Sat, 25 Jul 2009 13:22:21 +0000

Scientists at the Indian Institute of Science in Bangalore, along with researchers in Italy, have found two types of liquid water that have long been suspected to exist below water’s normal freezing point.

Unlike most liquids, water becomes less rather than more dense when it freezes — and it is densest not when it is coldest (at 0 degrees Celsius, just before it freezes) but at 4 degrees C.

These are just two of water’s host of anomalous properties, some of which are crucial to its behaviour in the natural environment.

In 1992, Gene Stanley of Boston University, Massachusetts, and his co-workers carried out computer simulations of water, which suggested that hydrogen bonds in water might produce two different types of liquid if water was made very cold and squeezed to high pressures.

In one form, the hydrogen bonds create a rather open, sparse network of water molecules, called low-density liquid (LDL) water. In the other, water molecules press closer at the cost of breaking some hydrogen bonds, forming a high-density liquid (HDL).

Stanley and his colleagues found that the two types of liquid water changed from one to the other in an abrupt ‘phase transition’, like the freezing/melting transition that separates ice and ordinary liquid water.

In this view, anomalies such as the density maximum at 4 degrees C are a reflection of the same competition between dense and less-dense states that creates the phase transition at much lower temperatures.

Now, Dino Leporini of the University of Pisa in Italy and his co-workers at the Indian Institute of Science in Bangalore say they have seen the two phases that Stanley’s team proposed in 1992.

The team used a technique called electron spin resonance to study the mobility of water molecules within tiny pockets of liquid trapped between crystallites of ice at temperatures down to around –183 degrees C.

They report that between about –140 and 0 degrees C, they can see two types of ‘liquid-like’ motion of the TEMPOL probes, presumably reflecting the presence of two types of water in the ice pockets.

One is slower than the other, and they interpret this as evidence for the presence of two distinct types of water: the more viscous LDL form, and the more fluid HDL.

According to Debenedetti, the results seem to reveal two different types of water, whose relative amounts change as the temperature changes.

source: http://www.aniin.com/