Sunday, October 19, 2014
My November Trip Highlights – Month 3: "Singapore is clean It is illegal to buy chewing gum and you can be heavily fined if caught spitting on the ground. I remember filling out my disembarkation card as I arrived into the country and on the bottom in capital, bolded red letters it read: “WARNING DEATH TO DRUG TRAFFICKERS UNDER SINGAPORE LAW.” Driving is also expensive, as the government uses regulations to discourage driving and encourage bikes and public transport. Before you can even buy a car you have to buy a certificate of entitlement, which changes based on your car and the horsepower. For example, Vanessa’s dad’s BMW had a certificate costing around $80,000. The government uses the certificate as a way to regulate vehicles by raising or dropping the price. Once you have a certificate, you still have to buy a car, then you have to decide what kind of registration you want. There are 3 different levels, designated by license plate color. A black license plate means you can drive whenever, a red plate means you can drive during the evening on weekdays and anytime on weekends and a yellow plate means you have to drive during the evening, except Sunday, which has no restrictions. And it doesn’t stop there. The government sets up electronic toll roads and you must buy the cashcard reader for your car. Toll roads litter the expressways and arterial roads with heavy traffic to discourage use during peak hours and as a way to lower traffic usage. Further, it is illegal to have a car in Singapore over 10 years old, unless you do major engine re-hauls. I found it all fascinating, but what I really noticed was how clean the country was, everywhere."
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Friday, October 17, 2014
Clean Energy commissioned the study to provide up-to-date information to the province, which is expected to make a decision on Site C before the end of the year.
“If government is going to make a decision, then let’s make sure at least that we put our best foot forward and let’s commission this study,” Clean Energy executive director Paul Kariya said on Thursday.
“What government does with the study, whether they agree or disagree – we’ve got that dialogue going on right now.”
That dialogue is taking place as the government mulls whether to proceed with Site C, which would be the third dam on B.C.’s Peace River and has a current price estimate of $7.9-billion.
The project, first proposed in the 1970s, cleared significant hurdles this week when it received environmental approvals from the federal and provincial governments.
But it faces questions about its potential cost and even whether it is needed to meet future energy needs.
B.C. Hydro says the province’s electricity needs are expected to grow by about 40 per cent over the next 20 years, that conservation and efficiency programs won’t be enough to fill the gap and that Site C is the best option when financial, technical, environmental and economic factors are taken into account.
Clean Energy’s new report challenges that position, and maintains the province could save up to $1-billion over 70 years – the projected life of the Site C dam – by pursuing smaller projects including wind installations and run-of-river hydro projects.
Such projects have a contentious history in B.C., including concerns about environmental impacts from river hydro installations over the past decade.
Wednesday, October 15, 2014
New Li-Ion Batteries Charge 70 Percent in 2 Minutes, Last for 20 Years: "A team of researchers in Singapore have developed a next generation lithium-ion battery that can recharge a battery to 70-percent in just two minutes. That means it would charge an entire electric car in just 15 minutes. And here's the kicker: it lasts over 20 years. Normally, it's safe to be skeptical about new battery technology, but there's something rather hopeful about this breakthrough. The new battery isn't altogether new. It's actually just an improvement upon existing lithium-ion technology. The key comes in the form of nanostructures. Instead of the traditional graphite used to create the lithium-ion battery's anode, this new technology uses a cheap titanium dioxide gel, the same kind of material used in sunscreen to absorb UV rays. The scientists found away to turn the compound into nanostructures that speed up the charging process. And speed it up they do. This simple innovation makes lithium-ion batteries charge 20-times faster and last 20-times longer. "With our nanotechnology, electric cars would be able to increase their range dramatically with just five minutes of charging, which is on par with the time needed to pump petrol for current cars," Associate Professor Chen Xiaodong of Nanyang Technological University said in a release. Just imagine what it could do for your smartphone. How To Take Care of Your Smartphone Battery the Right Way Your smartphone is a minor miracle, a pocket-sized computer that can fulfill almost every whim. But … Read more The researchers say they'll have the new technology on the market in just two years. While we've certainly seen fast-charging battery promises in the past, the simple fact that this new battery uses so much existing technology is reason to believe that they're right about that timeline, too. [NTU] "
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Thursday, October 9, 2014
A new method for transferring energy from organic to inorganic semiconductors could boost the efficiency of widely used inorganic solar cells.
The key to making a better solar cell is to be able to extract the electrons from these dark triplet excitons
Researchers have developed a new method for harvesting the energy carried by particles known as ‘dark’ spin-triplet excitons with close to 100% efficiency, clearing the way for hybrid solar cells which could far surpass current efficiency limits.
The team, from the University of Cambridge, have successfully harvested the energy of triplet excitons, an excited electron state whose energy in harvested in solar cells, and transferred it from organic to inorganic semiconductors. To date, this type of energy transfer had only been shown for spin-singlet excitons. The results are published in the journal Nature Materials.
In the natural world, excitons are a key part of photosynthesis: light photons are absorbed by pigments and generate excitons, which then carry the associated energy throughout the plant. The same process is at work in a solar cell.
In conventional semiconductors such as silicon, when one photon is absorbed it leads to the formation of one free electron that can be extracted as current. However, in pentacene, a type of organic semiconductor, the absorption of a photon leads to the formation of two electrons. But these electrons are not free and they are difficult to pin down, as they are bound up within ‘dark’ triplet exciton states.
Excitons come in two ‘flavours’: spin-singlet and spin-triplet. Spin-singlet excitons are ‘bright’ and their energy is relatively straightforward to harvest in solar cells. Triplet-spin excitons, in contrast, are ‘dark’, and the way in which the electrons spin makes it difficult to harvest the energy they carry.
“The key to making a better solar cell is to be able to extract the electrons from these dark triplet excitons,” said Maxim Tabachnyk of the University’s Cavendish Laboratory, the paper’s lead author. “If we can combine materials like pentacene with conventional semiconductors like silicon, it would allow us to break through the fundamental ceiling on the efficiency of solar cells.”
Using state-of-art femtosecond laser spectroscopy techniques, the team discovered that triplet excitons could be transferred directly into inorganic semiconductors, with a transfer efficiency of more than 95%. Once transferred to the inorganic material, the electrons from the triplets can be easily extracted.
“Combining the advantages of organic semiconductors, which are low cost and easily processable, with highly efficient inorganic semiconductors, could enable us to further push the efficiency of inorganic solar cells, like those made of silicon,” said Dr Akshay Rao, who lead the team behind the work.
The team is now investigating how the discovered energy transfer of spin-triplet excitons can be extended to other organic/inorganic systems and are developing a cheap organic coating that could be used to boost the power conversion efficiency of silicon solar cells.
The work at Cambridge forms part of a broader initiative to harness high tech knowledge in the physical sciences to tackle global challenges such as climate change and renewable energy. This initiative is backed by the UK Engineering and Physical Sciences Research Council (EPSRC) and the Winton Programme for the Physics of Sustainability.
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Thursday, October 2, 2014
Geo-engineering: Methane-Eating Microbes Need Trace Metal: "The study was recently published online in the journal Environmental Microbiology. The research was sponsored by the Department of Energy, NASA Astrobiology Institute and the National Science Foundation. Glass conducted the research while working as a NASA Astrobiology post-doctoral fellow at the California Institute of Technology, in the laboratory of professor Victoria Orphan. The methane-eating organisms, which live in symbiosis, consume methane and excrete carbon dioxide. “Essentially, they are eating it,” Glass said. “They are using some of the methane as a carbon source and most of it as an energy source.” Phylogenetically speaking, one microbial partner belongs to the Bacteria, and the other is in the Archaea, representing two distinct domains of life. The archaea is named ANME, or anaerobic methanotrophic archaea, and the other is a sulfate-utilizing deltaproteobacteria. Together, the organisms form “beautiful bundles,” Glass said. For a close-up view of the action on the sea floor, the research team used the underwater submersible robot Jason. The robot is an unmanned, remotely operated vehicle (ROV) and can stay underwater for days at a time. The research expedition in which Glass participated was Jason’s longest continuous underwater trip to date, at four consecutive days underwater. The carbon dioxide excreted by the microbes reacts with minerals in the water to form calcium carbonate. As the researchers saw through Jason’s cameras, calcium carbonate has formed an exotic landscape on the ocean floor over hundreds of years. “There are giant mountains on the seafloor of calcium carbonate,” Glass said. “They are gorgeous. It looks like a mountain landscape down there.” While on the seafloor, Jason’s robotic arm collected samples of sediment. Back in the lab, researchers sequenced the genes and proteins in these samples. The collection of genes constitutes the meta-genome of the sediment, or the genes present in a particular environment, and likewise the proteins constitute a metaproteome. The research team discovered evidence that an enzyme used by microbes to “eat” methane may need tungsten to operate. The enzyme (formylmethanofuran dehydrogenase) is the last in the pathway of converting methane to carbon dioxide, an essential step for methane oxidation. Microorganisms in low temperature environments typically use molybdenum, which has similar chemical properties to tungsten but is usually much more available (tungsten is directly below molybdenum on the periodic table). Why these archaea appear to use tungsten is unknown. One guess is that tungsten may be in a form that is easier for the organisms to use in methane seeps, but that question will have to be answered in future experiments."
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