Tuesday, 29 March 2011

First Practical Artificial Leaf Developed

Speaking in Anaheim, California at the 241st National Meeting of the American Chemical Society, scientists have described the advanced solar cell, about the size of a playing card, which imitates photosynthesis.

It has long been a goal of scientists working towards sustainable energy to develop an artificial leaf. The device shows promise for a cheap source of electricity especially in third world countries, and it is thought that just one of them could power the average house in most developing nations.

Optically the device has however nothing in common with the natural counterpart. It is made from silicon, different electronic parts and several catalyst substances, which accelerate and start reactions that would otherwise not happen. To use the device it is placed in water, where it splits water into Hydrogen and Oxygen. These are then put into a fuel cell, which uses them to produce electricity. This fuel cell could be located on top of a house or next to it.

At the moment the artificial leaf is already about 10 times more efficient at carrying out photosynthesis than a natural leaf, but the team is confident that they can boost both efficiency and lifetime of the device significantly in the near future.

sorry guys for my rather long absence. I've been busy with school and I will probably be busy with school for quite some time to come. I'll go through all your blogs soon and catch up on what I missed.

Sunday, 6 March 2011

Is pulling objects with light possible? How far away are we from tractor beams?

It is a known fact that light has the ability to push objects away. This is used in the concept of solar sails, which I explained in the first post on this blog.

In a new development though, researchers from Hong-Kong and China have calculated what is needed for a laser to pull instead of push. This can not be achieved with normal lasers, instead the researchers used what is known as a Bessel beam. They have a few rather unusual properties, for example they can re-assemble themselves. With conventional lasers, if you place an obstruction in their path they stop, whereas Bessel beams continue behind the object.
This allows the energy of the beam to be precisely controlled, and allows them to place more energy behind an object than in front of it, pushing it towards the source of the beam.

A close up, head on, view of a Bessel beam. (Credit: California Institute of Technology)

Rather than in science fiction however the effect is only predicted to occur over small distances, and will therefore mainly impact particle science. We unfortunately won't be able to use this to levitate or pull enemy space ships into our hangar, but it is fascinating none the less.

"Light can indeed pull a particle," the researchers wrote.

Friday, 4 March 2011

Synthetic Cells - How close are we to creating life?

Only last year, Craig Ventner, a known Human Genome sequencer, managed to inject completely synthetic DNA, into another cell, which then managed to reproduce. The goal of his research was to create bacteria that could be used to control CO2 levels in the atmosphere by converting it to other non-greenhouse gases.

Creating life some would argue, while other say that really all he did was make a synthetic replicate of life, a copy. Regarding the actual production and creation of new life, research is at its beginning.
In the visions of Bio-engineers, there are truly amazing things yet to come. DNA code that instead of two basepairs contains three, an alternate, new genetic code, which could increase the amount of possible combinations massively. Completely new amino acids, and therefore proteins could be created.

There are other potential uses for bio-engineered cells. Researchers in Edinburgh presented microorganisms capable of detecting arson in drinking water, in 2006, ideas about biological circuits have been in discussion for a long time.

But there are of course also other more sinister uses for these kinds of manipulations of life. Extinct strains of long dead diseases could be brough back, or even worse modified. The horrible biological weapons that are possible with this kind of technology are hard to imagine.

As of yet, however most of what has been done is the synthetic recreation of existing DNA. Little original life has been made, also due to problems with the synthesising of other cell parts. While making cell proteins is less of a problem, making the different cell membranes and organelles is more difficult, and only recently a new experimental way was found to make them in a regular way.

Artist's rendering of cell structure. (Credit: iStockphoto/Sebastian Kaulitzki)

So since this is a bit of a long one:

Tl;dr: Synthetic cells, have not yet been made, but due to recent advances will probably soon be made.

Basically I will try to post once every two days, although I don't have much time during the week, due to school etc.

Wednesday, 2 March 2011

Multi-Core Voltage regulators could lead to better energy usage

Electronic apps today are expected to be ever smaller. Smart phones are expected to have GPS, w-lan, multiple apps running at the same time and be capable of playing music, but if the battery time is at 4 hours the phone has only so much use.

To promote energy efficiency Harvard graduate Wonyoung Kim has developed and demonstrated a new device with the potential to reduce the power usage of modern processing chips. The “multi-core voltage regulator” (MCVR), almost instantly responds to changes in demand of voltage, which has the potential to solve the mismatch between power and demand.

(Credit: Image courtesy of Wonyoung Kim, Harvard School of Engineering and Applied Sciences)

Imagine you’re listening to music your iPod MP3 player, the graphics and images processor doesn’t necessarily need power, and similarly if you’re looking at photos the audio processor or the hd video processor don’t need power. Essentially it is faster than other devices like it. It can decrease the voltage supplied by 1Volt in less than 20 nanoseconds. Additionally it uses an algorithm that recognises which parts of the processor aren’t in use at the moment and cuts power to them.

The fact that the device is on the chip means that even individual cores on one processor chip can be managed individually. The short distances between the MCVR and the processor chip further reduce time between changes in voltage.

The biggest supply currently for this device would be in the mobile phone market, although it could also be used in laptops to reduce the heat output of the processor which is currently the obstacle to slimmer laptops.

The device is also readily implemented in current chip designs, meaning that it doesn’t need radical changes in the way chips look, instead in can be incorporated in the chip design.