QuoteReplyTopic: Science and Nature News Redux Posted: 24-Mar-2012 at 14:37
Better solar cell developed
In the future, windows could be sprayed with the newly developed carbon nanotube solar cells and used to generate electricity.
Imagine a world where the windows of high-rise office buildings are powerful energy producers, offering its inhabitants much more than some fresh air, light and a view. For the past four years a team of researchers from Flinders University has been working to make this dream a reality – and now the notion of solar-powered windows could be coming to a not too distant future near you.
As part of his just-completed PhD, Dr Mark Bissett from the School of Chemical and Physical Sciences has developed a revolutionary solar cell using carbon nanotubes.
A promising alternative to traditional silicon-based solar cells, carbon nanotubes are cheaper to make and more efficient to use than their energy-sapping, silicon counterparts.
“Solar power is actually the most expensive type of renewable energy – in fact the silicon solar cells we see on peoples’ roofs are very expensive to produce and they also use a lot of electricity to purify,” Dr Bissett said.
“The overall efficiency of silicon solar cells are about 10 per cent and even when they’re operating at optimal efficiency it could take eight to 15 years to make back the energy that it took to produce them in the first place because they’re produced using fossil fuels,” he said.
Dr Bissett said the new, low-cost carbon nanotubes are transparent, meaning they can be 'sprayed' onto windows without blocking light, and they are also flexible so they can be weaved into a range of materials including fabric – a concept that is already being explored by advertising companies.
While the amount of power generated by solar windows would not be enough to completely offset the energy consumption of a standard office building, Dr Bissett said they still had many financial and environmental advantages.
“In a new building, or one where the windows are being replaced anyway, adding transparent solar cells to the glass would be a relatively small cost since the cost of the glass, frames and installation would be the same with or without the solar component,” Dr Bissett said.
“It’s basically like tinting the windows except they’re able to produce electricity, and considering office buildings don’t have a lot of roof space for solar panels it makes sense to utilise the many windows they do have instead.”
Dr Bissett said the technology mimics photosynthesis, the process whereby plants obtain energy from the sun.
“A solar cell is created by taking two sheets of electrically conductive glass and sandwiching a layer of functionalised single-walled carbon nanotubes between the glass sheets,” he said.
“When light shines on the cell, electrons are generated within the carbon nanotubes and these can be used to power electrical devices.”
Although small prototypes have been developed in the lab, he said the next step would be to test the carbon cells on an 'industrial stage'.
If all goes to plan, the material could be on the market within 10 years.
“When we first started the research we had no idea if it would work because we were the first in the world to try it so it’s pretty exciting that we’ve proved the concept, and hopefully it will be commercially available in a few year’s time,” Dr Bissett said.
Dr Bissett is a winner of Flinders inaugural Best Student Paper Award, a now annual program which aims to recognise excellence in student research across the University.
Even women who ate chicken or pork but avoided red meat were twice as likely to be depressed or anxious. But don't go overboard - eating too much red meat is also related to mental health problems, the research found.
Deakin University health researchers have found that eating less than the recommended amount of red meat is related to depression and anxiety in women. Associate Professor Felice Jacka and colleagues from Deakin’s Barwon Psychiatric Research Unit based at Barwon Health investigated the relationship between the consumption of beef and lamb and the presence of depressive and anxiety disorders in more than 1000 women from the Geelong region. The results are published in the current edition of the journal Psychotherapy Psychosomatics.
“We had originally thought that red meat might not be good for mental health, as studies from other countries had found red meat consumption to be associated with physical health risks, but it turns out that it actually may be quite important,” Associate Professor Jacka said.
“When we looked at women consuming less than the recommended amount of red meat in our study, we found that they were twice as likely to have a diagnosed depressive or anxiety disorder as those consuming the recommended amount.
“Even when we took into account the overall healthiness of the women’s diets, as well as other factors such as their socioeconomic status, physical activity levels, smoking, weight and age, the relationship between low red meat intake and mental health remained.
“Interestingly, there was no relationship between other forms of protein, such as chicken, pork, fish or plant-based proteins, and mental health.
“Vegetarianism was not the explanation either. Only 19 women in the study were vegetarians, and the results were the same when they were excluded from the study analyses.”
Associate Professor Jacka said that it didn’t seem to be a good idea to eat too much red meat either.
“We found that regularly eating more than the recommended amount of red meat was also related to increased depression and anxiety,” she said.
Given the results of this study, Associate Professor Jacka believes following the recommended weekly intake of red meat could boost our mental health.
“We already know that the overall quality of your diet is important to mental health. But it seems that eating a moderate amount of lean red meat, which is roughly 3-4 small, palm-sized serves a week, may also be important,” she said.
Associate Professor Jacka also suggests sticking with grass fed meats whenever possible.
“We know that red meat in Australia is a healthy product as it contains high levels of nutrients, including the omega-3 fatty acids that are important to mental and physical health. This is because cattle and sheep in Australia are largely grass fed. In many other countries, the cattle are kept in feedlots and fed grains, rather than grass. This results in a much less healthy meat with more saturated fat and fewer healthy fats.”
Graphene could help build a new generation of electronic devices, such as touch screens, solar panels and superfast computers.
Imagine a material that is just one atom thick, 300 times stronger than steel, harder than diamond, a fantastic conductor of heat and electricity and super-flexible to boot.
This might sound like the stuff of science fiction, but believe it or not, such a material already exists.
The name of this supermaterial is graphene and it’s one of the most exciting prospects in science today.
The researchers found a way to dampen external influences on the graphene, and could then observe electrons moving through their graphene three times faster than was previously possible.
This development could pave the way for a new generation of graphene-based devices including touch screens and solar panels.
More on the uses of graphene in a moment, but first: what is graphene?
Quite simply, graphene is a new structural form (or 'allotrope') of carbon – one of the most versatile elements in the universe. It was discovered in 2004 by Russian-born physicists Andre Geim and Konstantin Novoselov, who jointly received the 2010 Nobel Prize in Physics for their troubles.
Graphene is a single, flat layer of carbon atoms packed tightly into a two-dimensional honeycomb arrangement. The in-plane (two-dimensional) carbon-carbon bonds in graphene are the strongest bonds known to science. It is these bonds that give graphene its unbelievable mechanical strength and flexibility.
Graphene is essentially a single layer of graphite, the material found in pencil 'lead'. When you draw on paper with a pencil, weakly bound graphene sheets in the graphite spread over your paper like a pack of cards.
But because graphene is so thin – the thickness of a single carbon atom – it is extremely difficult to see. This is one of the reasons it took researchers so long to find graphene sheets among thicker stacks of graphite.
Despite being so thin, graphene is an excellent conductor of electricity. Electrons flow through graphene with almost zero electrical resistance. This unusual property, and the fact graphene is nearly invisible, makes it an ideal material for the transparent electrodes used in computer displays and solar cells.
While scientists have known about graphene since 2004, it was in 2010 that researchers from Samsung and Sungkyunkwan University took a critical step in developing the commercial applications of this material.
They developed a scalable fabrication method which enabled them to produce transparent and flexible graphene electrodes measuring 30 inches (76 cm) diagonally. This method enabled them to manufacture multi-layer electrode films and incorporate these into a fully functional touch-screen panel device capable of withstanding high strain.
As a result of this development, it mightn’t be too long before graphene is powering the displays on your favourite electronic gadgets.
One of the most promising aspects of graphene is its potential as a replacement to silicon in computer circuitry. Graphene conducts electricity faster (at room temperature) than any other material, it produces very little heat dissipation and it consumes less power than silicon – the building block of modern computing.
These characteristics could make graphene ideal as the basis for superior signal processing components in superfast computers and mobile technologies.
But there are still many obstacles that need to be overcome.
Probably the biggest barrier is the low 'on-off current ratio' of current, superfast graphenetransistors. Put another way, electrons in graphene are almost unstoppable and therefore very hard to control. As a result it is almost impossible to set graphene transistors to an 'off' state.
If graphene is to compete with existing silicon technology, this on-off current ratio will need to be improved. In other words, we’ll need to find a way to control electrical currents within graphene transistors so we can turn them 'off'.
Many researchers are currently working on this exact problem, trying to gain control over the disobedient charge carriers by opening a gap in graphene’s “electronic band” – the part of the material that conducts electricity.
Graphene can also be modified to take on different properties than are found in its normal form. For instance, researchers have:
Each of these modifications has potential technological applications.
Graphene sheets can also be incorporated in different composite materials, harnessing graphene’s extraordinary mechanical, thermal and electrical properties. These composite materials could lead to stronger and lighter car and airplane parts, better electrical batteries and electricity-conducting, super-tough textiles.
But perhaps one of the most surprising and unusual graphene discoveries relates to membranes made of graphene oxide – a chemical derivative of graphene.
When these membranes were used to seal a metal container, not even the smallest gas molecule, such as helium, could penetrate the membrane. But when the researchers tried the same with water, they found the water could pass through the graphene-oxide membrane with no problems.
Although the principle behind this unusual behaviour is not yet understood, it could one day be used in the selective removal of water or other filtration applications.
This surprising result shows how much we still have to learn about graphene. If current research and development is anything to go by, we’ll be hearing plenty more about this amazing material in the years to come.
Brain Size May Determine Whether You Are Good at Keeping Friends
Friends. Researchers are suggesting that there is a link between the number of friends you have and the size of the region of the brain -- known as the orbital prefrontal cortex -- that is found just above the eyes.
Researchers are suggesting that there is a link between the number of friends you have and the size of the region of the brain -- known as the orbital prefrontal cortex -- that is found just above the eyes. A new study shows that this brain region is bigger in people who have a larger number of friendships.
Their study is published on 1 February 2012 in the journal, Proceedings of the Royal Society B.
The research was carried out as part of the British Academy Centenary 'Lucy to Language' project, led by Professor Robin Dunbar of the University of Oxford in a collaboration with Dr Joanne Powell and Dr Marta Garcia-Finana at Liverpool University, Dr Penny Lewis at Manchester University and Professor Neil Roberts at Edinburgh University.
The study suggests that we need to employ a set of cognitive skills to maintain a number of friends (and the keyword is 'friends' as opposed to just the total number of people we know). These skills are described by social scientists as 'mentalising' or 'mind-reading'- a capacity to understand what another person is thinking, which is crucial to our ability to handle our complex social world, including the ability to hold conversations with one another. This study, for the first time, suggests that our competency in these skills is determined by the size of key regions of our brains (in particular, the frontal lobe).
Professor Dunbar, from the Institute of Cognitive and Evolutionary Anthropology, explained: '"Mentalising" is where one individual is able to follow a natural hierarchy involving other individuals' mind states. For example, in the play 'Othello', Shakespeare manages to keep track of five separate mental states: he intended that his audience believes that Iago wants Othello to suppose that Desdemona loves Cassio [the italics signify the different mind states]. Being able to maintain five separate individuals' mental states is the natural upper limit for most adults.'.......
Composite image: the left side is a laser-produced shock wave whilst the right is a simulation of a collapsing shock wave arising during the pre-galactic phase.
Scientists have used a laser to create magnetic fields similar to those thought to be involved in the formation of the first galaxies; findings that could help to solve the riddle of how the Universe got its magnetism.
Magnetic fields exist throughout galactic and intergalactic space, what is puzzling is how they were originally created and how they became so strong.
A team, led by Oxford University physicists, used a high-power laser to explode a rod of carbon, similar to pencil lead, in helium gas. The explosion was designed to mimic the cauldron of plasma -- an ionized gas containing free electrons and positive ions -- out of which the first galaxies formed.
The team found that within a microsecond of the explosion strong electron currents and magnetic fields formed around a shock wave. Astrophysicists took these results and scaled them through 22 orders-of-magnitude to find that their measurements matched the 'magnetic seeds' predicted by theoretical studies of galaxy formation.
A report of the research is published in a recent issue of the journal Nature.
'Our experiment recreates what was happening in the early Universe and shows how galactic magnetic fields might have first appeared,' said Dr Gianluca Gregori of Oxford University's Department of Physics, who led the work at Oxford. 'It opens up the exciting prospect that we will be able to explore the physics of the cosmos, stretching back billions of years, in a laser laboratory here on Earth.'
The results closely match theories which predict that tiny magnetic fields -- 'magnetic seeds' -- precede the formation of galaxies. These fields can be amplified by turbulent motions and can strongly affect the evolution of the galactic medium from its early stages.
Dr Gregori said: 'In the future, we plan to use the largest lasers in the world, such as the National Ignition Facility at the Lawrence Livermore National Laboratory in California (USA), to study the evolution of cosmic plasma.'
The experiments were conducted at the Laboratoire pour l'Utilisation de Lasers Intenses laser facility in France.
Magnetic Field Researchers Target 100-Tesla Goal: Previous World Record Shattered During Six-Experiment Pulse
The 1,200-megajoule motor generator that powers the magnetic pulse.
Researchers at Los Alamos National Laboratory's biggest magnet facility have just met the grand challenge of producing magnetic fields in excess of 100 tesla while conducting six different experiments. The hundred-tesla level is roughly equivalent to 2 million times Earth's magnetic field.
"This is our moon shot, we've worked toward this for a decade and a half," said Chuck Mielke, director of the Pulsed Field Facility at Los Alamos.
The team used the 100-tesla pulsed, multi-shot magnet, a combination of seven coils sets weighing nearly 18,000 pounds and powered by a massive 1,200-megajoule motor generator. There are higher magnetic fields produced elsewhere, but the magnets that create such fields blow themselves to bits in the process. The system at Los Alamos is instead designed to work nondestructively, in the intense 100-tesla realm, on a regular basis. The Los Alamos facility is one of three campuses forming the National High Magnetic Field Laboratory (NHMFL).
Today's 100.75-tesla performance produced research results for scientific teams from Rutgers University, École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), McMaster University, University of Puerto Rico, University of Minnesota, Cambridge University, University of British Columbia, and Oxford University. The science that we expect to come out varies with the experiment, but can be summarized as:
Quantum Phase transitions and new ultra high field magnetic states
Electronic Structure determination
Topologically protected states of matter
"Congratulations to the Los Alamos team and our collaborators," said LANL Director Charlie McMillan. "Their innovations and creativity are not only breaking barriers in science, but solving national problems in the process."........
Getting the Dirt On Immunity: Scientists Show Evidence for Hygiene Hypothesis
This concept of exposing people to germs at an early age (i.e., childhood) to build immunity is known as the hygiene hypothesis.
Previous human studies have suggested that early life exposure to microbes (i.e., germs) is an important determinant of adulthood sensitivity to allergic and autoimmune diseases such as hay fever, asthma and inflammatory bowel disease.
This concept of exposing people to germs at an early age (i.e., childhood) to build immunity is known as the hygiene hypothesis.
Medical professionals have suggested that the hygiene hypothesis explains the global increase of allergic and autoimmune diseases in urban settings. It has also been suggested that the hypothesis explains the changes that have occurred in society and environmental exposures, such as giving antibiotics early in life.
However, neither biologic support nor a mechanistic basis for the hypothesis has been directly demonstrated. Until now.
Researchers at Brigham and Women's Hospital (BWH) have conducted a study that provides evidence supporting the hygiene hypothesis, as well as a potential mechanism by which it might occur.
The study was published online in the journal Science on the Science Express Web site on March 22, 2012.
The researchers studied the immune system of mice lacking bacteria or any other microbes ("germ-free mice") and compared them to mice living in a normal environment with microbes.
They found that germ-free mice had exaggerated inflammation of the lungs and colon resembling asthma and colitis, respectively. This was caused by the hyperactivity of a unique class of T cells (immune cells) that had been previously linked to these disorders in both mice and humans.
Most importantly, the researchers discovered that exposing the germ-free mice to microbes during their first weeks of life, but not when exposed later in adult life, led to a normalized immune system and prevention of diseases.
Moreover, the protection provided by early-life exposure to microbes was long-lasting, as predicted by the hygiene hypothesis.......
The study found that Australia's prolonged whooping cough epidemic has been predominantly caused by the new strain of the disease.
Australia’s prolonged whooping cough epidemic has entered a disturbing new phase, with a study showing a new strain or genotype capable of evading the vaccine may be responsible for the sharp rise in the number of cases. A team of Australian scientists, led by the University of New South Wales (UNSW), believe this emerging new genotype (called prn2-ptxP3) of the Bordetella pertussis bacterium may be evading the protective effects of the current acellular vaccine (ACV), and increasing the incidence of the potentially fatal respiratory illness, according to the study published in The Journal of Infectious Diseases.
The new genotype also has been detected in other countries, suggesting it has the potential to spark epidemics elsewhere and should be closely monitored, the researchers warn.
“The prolonged whooping cough epidemic in Australia that began during 2008 has been predominantly caused by the new genotype of B. pertussis,” said one of the study authors, Associate Professor Ruiting Lan, of the UNSW School of Biotechnology and Biomolecular Sciences.
“The genotype was responsible for 31% of cases in the 10 years before the epidemic, and that’s now jumped to 84% – a nearly three-fold increase, indicating it has gained a selective advantage under the current vaccination regime.
“The vaccine is still the best way to reduce transmission of the disease and reduce cases, but it appears to be less effective against the new strain and immunity wanes more rapidly. We need to look at changes to the vaccine itself or increase the number of boosters,” Associate Professor Lan said.
Last year about 38,000 cases of the life-threatening disease were reported nationally, despite Australians having a relatively high vaccine uptake.
The authors said the increase in the number of whooping cough notifications may be partly due to recent improvements in diagnostic tests, which means that mild or atypical cases in older children or adults are now more likely to be correctly identified. However, this does not explain the marked increase in hospital admissions, especially of very young children who are not fully immunised, in whom the diagnosis is much easier.
Associate Professor Lan's laboratory team – led by postdoctoral research associate Dr Sophie Octavia – analysed close to 200 samples of the B. pertussis bacterium, collected from 2008 to 2010 over four states, NSW, Vic, SA and WA.
The team worked closely with researchers from the Centre for Infectious Diseases and Microbiology at Westmead (A/Prof Vitali Sintchenko and Prof Lyn Gilbert), Women's and Children's Hospital, Adelaide (Dr Andrew Lawrence), Princess Margaret Hospital for Children, Perth (Dr Tony Keil); and Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne (Dr Geoff Hogg).
The findings suggest that while the current vaccination remains effective against most forms of whooping cough, its use could be contributing to the emergence of new and potentially more dangerous clones, Associate Professor Lan said.
First introduced in Australia in 1997, the ACV vaccination replaced the whole-cell vaccine (WCV), due to concerns about the latter’s side-effects.
“The whole cell vaccine contained hundreds of antigens, which gave broad protection against many strains of B. pertussis," said Associate Professor Lan. "But the acellular vaccine contains only three to five antigens.
“If the ACV is less effective against these new strains, we need to ask what other strategies can be used to combat the epidemic, which is ongoing."
There has been growing concern among public health officials about the rising incidence of whooping cough in Australia. The death rate for babies under the age of six months who catch pertussis is one in 200, according to NSW Health, which says adults and adolescents are at particular risk of contracting the disease and can pass it on to babies who are too young to be immunised.
In NSW, vaccinations are routinely given to infants at two, four and six months. The first dose can be given as early as 6 weeks of age. Boosters are needed at age four and again in high school. NSW Health also recommends that new parents and carers of young infants receive boosters.
James Cameron Now at Ocean's Deepest Point
Explorer-filmmaker reaches Mariana Trench on deepest ever solo sub dive.
At 5:52 p.m. ET Sunday (7:52 a.m. Monday, local time), James Cameron arrived at the Mariana Trench's Challenger Deep, members of the National Geographic expedition have confirmed. His depth on arrival: 35,756 feet (10,898 meters)—a figure unattainable anywhere else in the ocean. Reaching bottom after a 2-hour-and-36-minute descent, the National Geographic explorer and filmmaker typed out welcome words for the cheering support crew waiting at the surface: "All systems OK."
Folded into a sub cockpit as cramped as any Apollo capsule, the National Geographic explorer and frilmmaker is now investigating a seascape more alien to humans than the moon. Cameron is only the third person to reach this Pacific Ocean valley southwest of Guam (map)—and the only one to do so solo.
Cassini to Make Closest Pass Yet over Enceladus South
PoleThe intrepid little bird dips close... let us hope her wings are not clipped by the ice storms.
Do not anger Your Bacterias people cause: "Using this form of cell-to-cell communication, colonies of billions or
trillions of bacteria can literally reach a consensus on actions that
impact people...In other words I suppose they develop us as milky farms! http://www.sciencedaily.com/releases/2012/03/120327215704.htm
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Topic: Science and Nature News Redux
