The Fixing Carbon Scrubber

Are you one of the person who is in race to save the earth? want to help to reduce Global Warming ? then this is something you should know.
Carbon Scrubber -
a prototype for fixing carbon dioxide from atmosphere around you.
carbon scrubber is a device that is basically consist of honeycomb fillters,soduim hydroxide and a fan to extract air from atmosphere. exracted air is sprayed with NaOH solution and filtered air is expelled out. When this devide was tested it extract 430 kg air and filtered out 25kg carbon dioxide from it. isnt it great!!!!
click for video here   to see how this scrubber works exactly.though this scrubber is a great discovery but to bring it into commercial use it has still few hurdels among which cost is the important factor.
i request people to use various ways to save the environement around you else the deadline for earth to finish is not so far.

Reduce Global Warming. Save Earth. Save yourself.

If anyone reads this blog please comment and discuss how we can help to reduce global warming.


with love and peace
Abhinav Harlalka

DNA Stretching

i was just surfing through some recent science and innovation updates and i found one of the most research project which is being given emphasis in many labs across world that is " Stretching of DNA". i am not a biology person so couldn't understand it much but would like to.
According to recent results

Researchers in Europe have literally unravelled a mystery that has been puzzling scientists for years: what happens to a molecule of DNA when it is stretched to its breaking point. The question is important because DNA is subjected to a range of mechanical manipulations within the cell: it can be folded, unfolded, coiled and uncoiled, unzipped and zipped up again. A detailed understanding of the elastic properties of DNA can give scientists key insights into interactions of DNA and the proteins that carry out these manipulations.

Almost two decades ago it was shown that when a molecule of double-stranded DNA is pulled from either end, it undergoes a peculiar transition. Initially the molecule resists stretching. Then, at a force of 65 piconewtons, the polymer suddenly surrenders and stretches to 1.7 times its original length with little additional force. It then becomes resistant to stretching once more.

research on strethcing of DNA from my point of view is imp may be for the study of enzymes interacting with Dna or to obtain some kind of genetic information..from 1997 research is going on this project and still scientist are working on.
here are some links for more information

http://www.rsc.org/chemistryworld/News/2009/October/19100902.asp

http://www.sciencedaily.com/releases/2006/12/061206091654.htm#

http://www.lbl.gov/Science-Articles/Archive/PBD-stretched-DNA.html

if anyone of you could understand this aspect mcuh better pls feel free to comment.
With love & peace
Abhinav

 Controlling carbon nanotubes

Nanoscopic tubes made of a lattice of carbon just a single atom deep hold promise for delivering medicines directly to a tumor, sensors so keen they detect the arrival or departure of a single electron, a replacement for costly platinum in fuel cells or as energy-saving transistors and wires.

Single-walled carbon nanotubes, made of a cheap and abundant material, have so much potential because their function changes when their atomic-level structure, referred to as chirality, changes. But for all their promise, building tubes with the right structure has proven a challenge.
A pair of Case Western Reserve University researchers mixed metals commonly used to grow nanotubes and found that the composition of the catalyst can control the chirality. In a letter published in Nature Materials, R. Mohan Sankaran, an assistant professor of chemical engineering at the Case School of Engineering, and Wei-Hung Chiang, who received his doctorate degree in chemical engineering in May, describe their findings.

"We have established a link between the structure of a catalyst and the chirality of carbon nanotubes," Sankaran said. "Change the catalyst structure by varying its composition, and you can begin to control the chirality of the nanotubes and their electrical and optical properties."

The chirality of a single-walled carbon nanotube describes how a lattice of carbon atoms is rolled into a tube. The rolling can occur at different angles, producing different structures that exhibit very different properties. Nanotubes are normally grown in bulk mixtures. When using a nickel catalyst, typically one-hird of those grown are metallic and could be used like metal wires to conduct electricity. About two-thirds are semiconducting nanotubes, which could be used as transistors, Chiang explained. But, separating them according to properties, "is costly and can damage the nanotubes." Chiang and Sankaran found that a mixed iron and nickel catalyst could change the outcome. Of the compositions tested, a catalyst of 27 percent nickel and 73 percent iron produced the most dramatic result: the vast majority of the nanotubes were semiconducting. They are now working on assessing the purity and integrating the nanotubes into thin film transistors. The authors say their findings open the door to experimenting with other elements as catalysts and different combinations, which may produce near-pure nanotubes with desired properties.



Original publication: "Linking catalyst composition to chirality distributions of as-grown single-walled carbon nanotubes by tuning NIxFe1-x nanoparticles."; Nature Material2009.

Solar cell : highest efficiency

Aussies help set new solar power world record

Australian solar cell researchers have played a key role in achieving the highest efficiency for solar power ever recorded, setting a new world record of 43 per cent of sunlight converted into electricity.

The team of Australian scientists, from the University of New South Wales, combined with two US groups to demonstrate a multi-cell combination which has set the new benchmark for converting sunlight into electricity by any possible approach.
"Because sunlight is made up of many colours of different energy, ranging from the high energy ultraviolet to the low energy infrared, a combination of solar cells of different materials can convert sunlight more efficiently than any single cell," said Martin Green, research director of the UNSW ARC Photovoltaics Centre of Excellence.

Green led the team that developed a silicon cell optimised to capture light at the red and near-infrared end of the light spectrum. That cell was able to convert up to 46 per cent of light in that colour range into electricity.
When combined with four other cells, each optimised for different parts of the solar spectrum, the five-cell combination converted 43 per cent of the sunlight hitting it into electricity, improving on the previous world record by 0.3 per cent.

Stuart Wenham, Director of the ARC Centre, said the new record was not directly comparable to the 25 per cent efficiency world record for an individual solar cell set by UNSW last year; however, it was an important pointer for the future potential of solar photovoltaic power.

The latest research will be published in the journal Progress in Photovoltaics in September

CNT growth without metal catalyst

Researchers make carbon nanotubes without metal catalyst

Carbon nanotubes - tiny, rolled-up tubes of graphite - promise to add speed to electronic circuits and strength to materials like carbon composites, used in airplanes and racecars. A major problem, however, is that the metals used to grow nanotubes react unfavorably with materials found in circuits and composites. But now, researchers at MIT have for the first time shown that nanotubes can grow without a metal catalyst. The researchers demonstrate that zirconium oxide, the same compound found in cubic zirconia "fake diamonds," can also grow nanotubes, but without the unwanted side effects of metal.


The implications of ditching metals in the production of carbon nanotubes are great. Historically, nanotubes have been grown with elements such as iron, gold and cobalt. But these can be toxic and cause problems in clean room environments. Moreover, the use of metals in nanotube synthesis makes it difficult to view the formation process using infrared spectroscopy, a challenge that has kept researchers in the dark about some of the aspects of nanotube growth.

"I think this fundamentally changes the discussion about how we understand carbon nanotubes synthesis," says Brian Wardle, professor of aeronautics and astronautics who led the study, published Aug. 10 in the online version of the Journal of the American Chemical Society.

Wardle adds that some researchers might find the result controversial since no one has ever proven that anything other than a metal can grow a nanotube. "People report new metals [as catalysts] every so often," he says. "But now we have a whole new class of catalyst and new mechanism to understand and debate."

The conventional model for nanotube growth goes like this: A substrate is sprinkled with nanoparticle seeds made of a certain metal, of the same diameter of the desired nanotubes. The substrate and nanoparticles are heated to 600 to 900 degrees Celsius, and then a carbon-containing gas such as methane or alcohol is added. At the high temperatures, molecules break apart and reassemble. Some of these carbon-containing molecules find their way to the surface of a nanoparticle where they dissolve and then precipitate out, in nanotube form.
The researchers found that if they just used zirconium oxide nanoparticles on the substrate, they could coax carbon into nanotubes as well. Importantly, the mechanism for growth seems to be completely different from that of metal nanoparticle-grown tubes. Instead of dissolving into the nanoparticle and precipating out, zirconia-grown nanotubes appear to assemble directly on the surface.
In collaboration with Professor Stephan Hofmann at the University of Cambridge in England, the MIT researchers took images of the oxide-based nanotubes using X-ray photoelectron spectroscopy during growth. This allowed them to see that when nanotubes formed, zirconium oxide persisted, and didn't form into a metal, bolstering their conclusions.

One of the most exciting implications of the finding is that it means that carbon fiber and composites, used to make different types of crafts, could be strengthened by nanotubes. "Composites are durable, but fail under certain loading conditions, like when plywood flakes and splinters apart," says Stephen Steiner, an MIT graduate student and the study's first author. "But what if you could reinforce composites at the microlevel with nanotubes the way that rebar reinforces concrete in a building or a bridge? That's what we're trying to do to improve the mechanical properties and resistance to fracturing of carbon composites."

Steiner says the reason that planes like Airbus' A380 and Boeing's new 787 are made of only 40 percent composites and not 90 percent is because composites aren't strong enough for all parts of the craft. But if they were bolstered by nanotubes, then the planes could be made of more composites, which would make them lighter, and less expensive to fly because they wouldn't need as much fuel.

The findings are already impressing researchers in industry. "This innovation has far-reaching implications for commercial productions of carbon nanotubes," says David Lashmore, CTO of Nanocomp Technologies Inc., a company in Concord, N.H., that was not involved in the research. "It for the first time allows the use of a ceramic catalyst instead of a magnetic transition metal, some of which are carcinogenic."


Wardle suspects that more oxide-based catalysts will be found in the coming years. He and his team will focus on trying to understand the fundamental mechanisms of this type of nanotube growth and help to contribute more types of catalysts to the nanotube-growing arsenal. While the researchers don't have a timeline, they suspect that it would be easy to commercialize the process as it's simple, adaptable and, in many ways, more flexible than growth with metal catalysts.

This work was supported by Airbus S.A.S., Boeing, Embraer, Lockheed Martin, Saab AB, Spirit AeroSystems, Textron Inc., Composite Systems Technology, and TohoTenax through MIT's Nano-Engineered Composite aerospace Structures (NECST) Consortium.

Nanocrystal real time growth

Real time nanocrystal growth in solution  for the first time

The veil is being lifted from the once unseen world of molecular activity. Not so long ago only the final products were visible and scientists were forced to gauge the processes behind those products by ensemble averages of many molecules. The limitations of that approach have become clear with the advent of technologies that allow for the observation and manipulation of single molecules. A prime example is the recent first ever direct observations in real-time of the growth of single nanocrystals in solution, which revealed that much of what we thought we knew is wrong.

Interim Berkeley Lab Director Paul Alivisatos and Ulrich Dahmen, director of Berkeley Lab’s National Center for Electron Microscopy (NCEM), led a team of experts in nanocrystal growth and electron microscopy who combined their skills to observe the dynamic growth of colloidal platinum nanocrystals in solution with subnanometer resolution. Their results showed that while some crystals in solution grow steadily in size via classical nucleation and aggregation - meaning molecules collide and join together - others grow in fits and spurts, driven by “coalescence events,” in which small crystals randomly collide and fuse together into larger crystals. Despite their distinctly different growth trajectories, these two processes ultimately yield a nearly monodisperse distribution of nanocrystals, meaning the crystals are all approximately the same size and shape.

“Coalescence events have been previously observed in flask synthesis of colloidal nanocrystals and has been considered detrimental for achieving monodisperse colloidal nanocrystals,” says Haimei Zheng, a chemist in Alivisatos’ research group, who was the lead author on a paper that reported these results in the journal Science. “In our study, we found that coalescence events are frequently involved in the early stage of nanocrystal growth and yet monodisperse nanocrystals are still formed.”

Says Alivisatos, a chemist who holds joint appointments with Berkeley Lab and the University of California at Berkeley where he is the Larry and Diane Bock professor of Nanotechnology, “This direct observation of nanocrystal growth trajectories revealed a set of pathways more complex than those previously envisioned and enables us to re-think the nanocrystal growth mechanism with an eye towards more controlled synthesis.”
These TEM images show comparisons between the nanocrystal growth trajectories of monomer attachments (a) and coalescence events (b). The Science paper was titled: “Observation of Single Colloidal Platinum Nanocrystal Growth Trajectories.” Co-authoring this paper with Zheng, Alivisatos and Dahmen were Rachel Smith, Young-wook Jun and Christian Kisielowski.
Nanocrystals are projected to play important roles in a wide-ranging number of technologies including solar and fuel cell, catalysis, electronics and photonics, medicine, and imaging and sensing. The key to success will be the ability to synthesis nanocrystals with desired physical properties. This will require a much better understanding of colloidal nanocrystal growth mechanisms. While the past two decades have seen tremendous advances in the synthesis of semiconductor, metal and dielectric nanocrystals, these advances have generally been realized through trial and error chemistry. A much more directed and controlled approach to nanocrystal synthesis is needed.

A new technique known as “liquid cell in situ transmission electron microscopy,” in which the powerful resolution capabilities of a transmission electron microscope (TEM) are brought to bear on a liquid cell that allows liquids to be observed inside a vacuum, enables the visualization of single nanoparticles in solution. The Berkeley researchers deployed this technique on NCEM’s JEOL 3010 In-Situ microscope. Utilizing an electron beam operating at 300 kilovolts of energy, the JEOL 3010 provides outstanding specimen penetration and spatial resolution of about 8 angstroms through the thick liquid cell sample.

“The JEOL 3010 In-Situ Microscope is our best machine for imaging dynamic events, and at 300kV the electron beam has enough penetrating power to maintain high resolution, even when looking through a liquid confined between two thin solid windows,” says NCEM director Dahmen. “Our resolution is significantly higher than any previous studies of this nature, which made it possible for us to measure the movement and growth of individual colloidal particles only a few nanometers in size.”

Haimei Zheng is a chemist in the research group of Paul Alivisatos who was the lead author on a Science paper that reports the first ever direct observations in real-time of the growth of single nanocrystals in solution. (Photo by Majed Abolfazli)

Zheng, Dahmen, Alivisatos and their colleagues used the JEOL 3010 and liquid cells microfabricated from a pair of 100-micron-thick silicon wafers with 20 nanometer thick silicon nitride membrane windows to image the growth trajectories of platinum nanocrystals in solution. Platinum nanocrystals are an ideal system for such studies because their high electron contrast allows liquid-cell TEM imaging of individual particles. The JEOL 3010’s electron beam was used to both trigger nucleation and drive crystal growth through reduction of the platinum cations.

“Video-rate acquisition allowed us to track nanocrystal growth trajectories from frame-to-frame,” says Zheng. “This allowed us to observe that each nanocrystal can either grow steadily through the addition of monomers from solution or by merging with another nanocrystal in random coalescence events.”

Zheng says it has been assumed that coalescence events would result in some crystals being much larger than others, a bad thing in that the physical properties of nanocrystals are so dependent upon size and shape that for many applications it is critical that monodispersed nanocrystals be produced during synthesis. Consequently, strategies such as the use of surfactants to coat nanocrystal surfaces have been adopted to avoid coalescence events.

“Our observations provide invaluable direct information on how nanocrystals grow and indicate how we might directly control nanocrystal synthesis for tailored properties,” says Zheng. “Also, our in situ liquid cell TEM technique can be applied to other areas of research such as soft matter imaging and nanoparticle catalysis, and offers great potential for addressing many fundamental issues in materials science, chemistry and other fields of science.”Says Dahmen, “From a microscopist’s point of view, the ability to observe nanoparticles in liquid solution opens new opportunities in an area that has traditionally been off-limits because electron microscopes require vacuum conditions. We can now see directly what before could only be surmised from the statistical behavior of the ensemble. It’s like understanding traffic by watching individual cars instead of listening to the traffic report.”

NCEM is a U.S. Department of Energy national user facility that is hosted at Berkeley Lab. Established in 1983, it stands today as one of the world’s foremost centers for electron microscopy and microcharacterization.
Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research for DOE’s Office of Science and is managed by the University of California.

Additional Information

For more information about the research of Paul Alivisatos visit the Website at http://www.cchem.berkeley.edu/pagrp/
For more information on the National Center for Electron Microscopy visit the Website at http://ncem.lbl.gov

Nano Bio updates

Nanoelectronic transistor combined with biological machine could lead to better electronics


LIVERMORE, Calif. -- If manmade devices could be combined with biological machines, laptops and other electronic devices could get a boost in operating efficiency.

Lawrence Livermore National Laboratory researchers have devised a versatile hybrid platform that uses lipid-coated nanowires to build prototype bionanoelectronic devices.


Mingling biological components in electronic circuits could enhance biosensing and diagnostic tools, advance neural prosthetics such as cochlear implants, and could even increase the efficiency of future computers.
While modern communication devices rely on electric fields and currents to carry the flow of information, biological systems are much more complex. They use an arsenal of membrane receptors, channels and pumps to control signal transduction that is unmatched by even the most powerful computers. For example, conversion of sound waves into nerve impulses is a very complicated process, yet the human ear has no trouble performing it.
“Electronic circuits that use these complex biological components could become much more efficient,” said Aleksandr Noy, the LLNL lead scientist on the project.
While earlier research has attempted to integrate biological systems with microelectronics, none have gotten to the point of seamless material-level incorporation.

“But with the creation of even smaller nanomaterials that are comparable to the size of biological molecules, we can integrate the systems at an even more localized level,” Noy said.
To create the bionanoelectronic platform the LLNL team turned to lipid membranes, which are ubiquitous in biological cells. These membranes form a stable, self-healing,and virtually impenetrable barrier to ions and small molecules.

“That's not to mention that these lipid membranes also can house an unlimited number of protein machines that perform a large number of critical recognition, transport and signal transduction functions in the cell,” said Nipun Misra, a UC Berkeley graduate student and a co-author on the paper.

Julio Martinez, a UC Davis graduate student and another co-author added: “Besides some preliminary work, using lipid membranes in nanoelectronic devices remains virtually untapped.”
The researchers incorporated lipid bilayer membranes into silicon nanowire transistors by covering the nanowire with a continuous lipid bilayer shell that forms a barrier between the nanowire surface and solution species.
“This 'shielded wire' configuration allows us to use membrane pores as the only pathway for the ions to reach the nanowire,” Noy said. “This is how we can use the nanowire device to monitor specific transport and also to control the membrane protein.”
The team showed that by changing the gate voltage of the device, they can open and close the membrane pore electronically.

The research appears Aug. 10 in the online version of the Proceedings of the National Academy of Sciences.

Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.