Science Sunday #12
Posted by Don McLenaghen on September 4, 2011
– and on the seventh day we learn.
Each week I hope to give a synopsis of the interesting science stories I have heard on my plethora of science podcasts I listen to each week plus anything I pick up scanning the inter-web. This week’s top stories:
Words of the Week:
Electrowetting – the modification of the wetting properties of a surface (which is typically hydrophobic ) with an applied electric field. Wetting is the ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. Electrowetting is now used in a wide range of applications from modulab to adjustable lenses, electronic displays (e-paper) and switches for optical fibers.
Probiotic – Probiotics are live microorganisms thought to be beneficial to the host organism. According to the currently adopted definition by FAO/WHO, probiotics are: “Live microorganisms which when administered in adequate amounts confer a health benefit on the host.”
To date, the European Food Safety Authority has rejected most claims that are made about probiotic products, saying they are unproven
Nanotechnology – OR nanotech; is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with structures sized between 1 to 100 nanometre in at least one dimension, and involves developing materials or devices possessing at least one dimension within that size. Quantum mechanical effects are very important at this scale.
Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale..
Eyes on the Solar System –
The “Eyes on the Solar System” interface combines video game technology and NASA data to create an environment for users to ride along with agency spacecraft and explore the cosmos. Screen graphics and information such as planet locations and spacecraft maneuvers use actual space mission data..
Emotions not so universal –
It has long been assumed that our facial expressions are part of our instinctual heritage and as such their interpretation universal among humanity. However recent research by Rachael E. Jack, PhD, of the University of Glasgow published by American Psychological Association has suggested that this may be a false assumption.
Some prior research has supported the notion that facial expressions are a hard-wired human behavior with evolutionary origins, so facial expressions wouldn’t differ across cultures. But this study challenges that theory and used statistical image processing techniques to examine how study participants perceived facial expressions through their own mental representations.
“By conducting this study, we hoped to show that people from different cultures think about facial expressions in different ways. East Asians and Western Caucasians differ in terms of the features they think constitute an angry face or a happy face.” Jack said.
“A mental representation of a facial expression is the image we see in our ‘mind’s eye’ when we think about what a fearful or happy face looks like,” Jack said. “Mental representations are shaped by our past experiences and help us know what to expect when we are interpreting facial expressions.”
“Our findings highlight the importance of understanding cultural differences in communication, which is particularly relevant in our increasingly connected world,” Jack said. “We hope that our work will facilitate clearer channels of communication between diverse cultures and help promote the understanding of cultural differences within society.”
World’s smallest electric motor –
Chemists at Tufts University’s School of Arts and Sciences have developed the world’s first single molecule electric motor, a development that may potentially create a new class of devices that could be used in applications ranging from medicine to engineering.
In research published online September 4 in Nature Nanotechnology, the Tufts team reports an electric motor that measures a mere 1 nanometer across, ground-breaking work considering that the current world record is a 200 nanometer motor. A single strand of human hair is about 60,000 nanometers wide.
Hydrogen fuel from sunlight from novel alloy –
Scientist at the UK Center for Computational Sciences, and Professor Mahendra Sunkara and the UofL Conn Center for Renewable Energy Research in a paper published in the Physical Review Journal, have determined that an inexpensive semiconductor material can be “tweaked” to generate hydrogen from water using sunlight.
Using state-of-the-art theoretical computations, the UK-UofL team demonstrated that an alloy formed by a 2 percent substitution of antimony (Sb) in gallium nitride (GaN) has the right electrical properties to enable solar light energy to split water molecules into hydrogen and oxygen, a process known as photo-electrochemical (PEC) water splitting. When the alloy is immersed in water and exposed to sunlight, the chemical bond between the hydrogen and oxygen molecules in water is broken. The hydrogen can then be collected.
Hydrogen has long been touted as a likely key component in the transition to cleaner energy sources. Pure hydrogen gas is not found in free abundance on Earth, it must be manufactured by unlocking it from other compounds. Thus, hydrogen is not considered an energy source, but rather an “energy carrier.” Currently, it takes a large amount of electricity to generate hydrogen by water splitting. As a consequence, most of the hydrogen manufactured today is derived from non-renewable sources such as coal and natural gas. The GaN-Sb alloy has the potential to convert solar energy into an economical, carbon-free or zero-emission source for hydrogen.
Mind-Altering Microbes –
Probiotic bacteria have the potential to alter brain neurochemistry and treat anxiety and depression-related disorders according to research published in the Proceedings of the National Academy of Sciences.
The research, carried out by Dr Javier Bravo, and Professor John Cryan at the Alimentary Pharmabiotic Centre in University College Cork, along with collaborators from the Brain-Body Institute at McMaster University in Canada, demonstrated that mice fed with Lactobacillus rhamnosus JB-1 showed significantly fewer stress, anxiety and depression-related behaviours than those fed with just broth. Moreover, ingestion of the bacteria resulted in significantly lower levels of the stress-induced hormone, corticosterone.
It must be noted however, that although the results were positive they were specific to mice. The bacteria used would, according to an interview on NPR’s Science Friday, not be appropriate for humans. Future research may show a similar connection between ‘human’ probiotic bacteria but any claims of efficacy of current product flouting their probiotic contents is at best pre-mature and at worst bad-thinking!
Nuclear power on Mars –
The first nuclear power plant being considered for production of electricity for manned or unmanned bases on the Moon, Mars and other planets may really look like it came from outer space, according to a leader of the project who spoke at the 242nd National Meeting & Exposition of the American Chemical Society (ACS).
James E. Werner said that innovative fission technology for surface power applications is far different from the familiar terrestrial nuclear power stations, which sprawl over huge tracts of land and have large structures such as cooling towers.
“People would never recognize the fission power system as a nuclear power reactor,” said Werner. “The reactor itself may be about 1 ½ feet wide by 2 ½ feet high, about the size of a carry-on suitcase. There are no cooling towers. A fission power system is a compact, reliable, safe system that may be critical to the establishment of outposts or habitats on other planets. Fission power technology can be applied on Earth’s Moon, on Mars, or wherever NASA sees the need for continuous power.”
The team is scheduled to build a technology demonstration unit in 2012.
Nuclear reactors can produce power in any environment. Fission power technology doesn’t rely on sunlight, making it able to produce large, steady amounts of power at night or in harsh environments like those found on the Moon or Mars. A fission power system on the Moon could generate 40 kilowatts or more of electric power, approximately the same amount of energy needed to power eight houses on Earth.” Werner explained.
“While the physics are the same, the low power levels, control of the reactor and the material used for neutron reflection back into the core are completely different,” Werner said. “Weight is also a significant factor that must be minimized in a space reactor that is not considered in a commercial reactor.”
Werner contends that once the technology is developed and validated, it may prove to be one of the most affordable and versatile options for providing long-term base power for the space exploration programs.
Shoe Power –
Although you may not be using a Get Smart-style shoe phone anytime soon, it is possible that your mobile phone may end up receiving its power from your shoes. University of Wisconsin-Madison engineering researchers Tom Krupenkin and J. Ashley Taylor have developed an in-shoe system that harvests the energy generated by walking. Currently, this energy is lost as heat. With their technology, however, they claim that up to 20 watts of electricity could be generated, and stored in an incorporated rechargeable battery.
Their new technique on the principle of electrowetting. Here, the shape of a liquid droplet sitting on a liquid-repelling surface is changed by applying voltage to the surface.
They use this principle in reverse, converting the energy of moving liquid into an electrical current. They experimented with a range of liquids but eventually settled on a liquid metal alloy called Galinstan that is used in thermometers, as it has similar properties to mercury but is nontoxic.