Revving Up Fuel Cells
Progress toward hydrogen-powered cars depends on less expensive but greater capacity fuel-cell systems [see “On the Road to Fuel-Cell Cars”; SciAm, March 2005]. Researchers have taken big steps on both the cost and storage challenges. A team from Quebec came up with a recipe that uses iron instead of expensive platinum to catalyze the electricity-making reaction of hydrogen and oxygen. The key was carbon structures containing microscopic pores, which were filled with iron to provide plenty of active sites for chemical reactions. The iron-based substance, described in the April 3 Science, produced catalytic activity within 10 percent of the best platinum versions and 35 times better than previous, nonprecious metal catalysts.
Pores are also driving the search for materials that can store hydrogen for delivery to fuel cells. A team from the University of Michigan at Ann Arbor says it has made a material that has a record-high surface area for holding gases. This hydrogen sponge consists of zinc oxide clusters linked by an organic material; one gram has the surface area of 5,000 square meters, nearly the size of a football field. Details of the substance, dubbed UMCM-2, appear in the April 1 Journal of the American Chemical Society.
New Heart Cells from the Atomic Age
Aboveground nuclear testing in the 1950s spewed radioactive carbon 14 and other isotopes worldwide. Plants soaked up the compounds, animals ate the plants, and humans ate both, inadvertently creating an experimental opportunity for Jonas Frisén of the Karolinska Institute in Stockholm and his colleagues. They have used the decay of atomic age carbon 14 as a biological marker to determine how frequently the body replaces its cells [see “Cold War Clues”; SciAm, December 2005]. With the data, they have settled a long-standing question by showing that humans can indeed produce new heart cells, or cardiomyocytes. The annual turnover rate is 1 percent at age 25, decreasing to 0.45 percent by age 75; all told, about 40 percent of cardiomyocytes are replaced by age 70. The finding, in the April 3 Science, suggests that stimulating the turnover mechanism could repair damaged hearts.
Not So Lifesaving
For years researchers have questioned the value of a blood test for prostate cancer, called a PSA test [see “Does Screening for Prostate Cancer Make Sense?”; SciAm, September 1996]. After all, most prostate cancers progress slowly, sometimes never posing a problem, and treatment could cause impotence and incontinence. First results from large, ongoing U.S. and European studies, published in the March 26 New England Journal of Medicine, suggest that the PSA test does not save many lives. The U.S.trial found no reduction in death from prostate screening in men followed for about 11 years. The European study, which had different protocols, saw a 20 percent drop in death rates, which translated to seven fewer deaths per 10,000 men screened and tracked for nine years. Expect follow-up work to resolve some of the differences between the two studies.
Lightning-Fast Warnings
Storms could become more intense as the world warms [see “Warmer Oceans, Stronger Hurricanes”; SciAm, July 2007]. Researchers studying 58 hurricanes found that an increase in lightning tended to precede the strongest winds by a day. For instance, monitors tracking Hurricane Dennis in 2005 recorded a surge in lightning flashes—from 600 a day to 1,500—nearly 24 hours before wind speeds doubled and peaked at 150 miles per hour. The correlation, reported online April 6 in Nature Geoscience, needs more data before lightning can be considered a definitive predictor of storm intensity.
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8 Comments
Add CommentStoring hydrogen in cars is impractical and dangerous. I think it would be better if the research is focused on ethanol and/or bio-diesel fuel cell instead. (like using them to charge the battery of a plug-in electric+ethanol fuel cell hybrid car for long distance trips).
Reply | Report Abuse | Link to thisStoring hydrogen in cars isn't impractical or dangerous.
Reply | Report Abuse | Link to thisIt COULD be done impractical and dangerous.
Or it could be done practical and safely.
Kneejerk decisions based on short-term viability of long-term technological directives are what led to the ICE idiocy of the last 100 years.
What's the big deal about trying to make cars run on hydrogen? Hydrogen is a form of energy, not a source of energy. So it's not a real game changer. You can store energy (derived from various sources of energy and probably transported as electrical energy) in batteries or as hydrogen. Either way, the key question is what the source of energy will be.
Reply | Report Abuse | Link to thisAbsolutely. Hydrogen is produced using electricity anyway. Plus hydrogen cars would require extensive production, transportation, gas station changes. Plug-in electric car is way more practical.
Reply | Report Abuse | Link to thisBLDP, PLUG, HYGS.. All doing fantastic today.
Reply | Report Abuse | Link to thisEnergy delivered to the drive train electrically from stored hydrogen energy has a theoretical efficiency around 80%. Hydrogen can be regenerated using electricity or a number of chemical reactions. Power generation using high-temperature gas turbines is much more efficient than internal combustion engines used today in most vehicles. Chemical energy is expensive to transport compared to electrical energy. Plug-in cars might be a viable option. However, they have their limitations too: range, replacement costs, weight of batteries, lifecycle costs of batteries including disposal and externalities like pollution. There is energy overhead inherent to the production of batteries. Batteries are typically just as dangerous or more dangerous than hydrogen stored at low pressure (such as this article describes). The above are not intended to argue against any other technology, but to list some of the attractive qualities of hydrogen energy as a storage medium.
Reply | Report Abuse | Link to thisFarmers cannot support both ethonol AND food requirments, it has been proved and spoken of before that even E80 requires too much demand for farmers to be able to keep up with and still be able to support the food industry. I think that fuel cells are a brillent idea and would have been perfected nearly a decade ago if it were not for the fossil fuel industry having so much power and crushing the hopes of an earlier cheap and geen future!!!
Reply | Report Abuse | Link to thisAnd it also depends on the state/provience/country that the electriciy is produced in. For example, the provience that i live in in Canada nearly 80% of the electricity is produced by coal power plants. If even a small percentage of people were to be using electric vehicles they would not be able to keep up and would be burning coal (the dirtiest fuel on the planet) to indirectly fuel their vehicles. Some places can power electric vehicles for next to nothing while using green means to produce it, but others will be using electricity generated by the dirtiest least green power on the planet which was mined in a third world country with no human rights. I love electric cars because they are so directly clean, but you have to keep in mind where the energy in which they are using is coming from as well. Hydrogen on the other hand can be produced via electrolysis anywhere via chemical or physical reactions and for very little cost. The largest cost being to the manufacturing companies and there for to the consumers, but in the long run a very good idea since the only by-product is H2O. But then again nearly the same goes for propane since it can be man made in a lab and it's only by-product is water as well.....all these ideas would be leaps and bounds further along if it wasn't for fossil fuel billionaires being so greedy and crushing the green industry with their big powerful dirty thumbs....
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