Thursday, March 11, 2010

MORE, BETTER BIODIESEL

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Yields of biodiesel from oilseed crops such as safflower could be increased by up to 24 percent using a new process developed by chemists at UC Davis. The method converts both plant oils and carbohydrates into biodiesel in a single process, and should also improve the performance characteristics of biodiesel, especially in cold weather.

A paper describing the method, which has been patented, is online in the journal Energy & Fuels.

Conventional biodiesel production extracts plant oils and then converts them into fatty acid esters that can be used to power engines, said Mark Mascal, professor of chemistry at UC Davis and co-author of the paper with postdoctoral researcher Edward Nikitin. That leaves behind the carbohydrate portion of the plant — the sugars, starches, and cellulose that make up stems, leaves, seed husks and other structures.

The new process converts those carbohydrates into chemicals called levulinic acid esters — at the same time and in the same vessel that the oils are converted to fatty acid esters — resulting in a fuel cocktail that performs better at low temperatures than conventional biodiesel.

The fuel cocktail has a similar boiling range to conventional biodiesel, but is thinner; it becomes waxy at a lower temperature. Performance at low temperatures is a significant problem with B100 (conventional biodiesel), Mascal said.

"Our hope is that this blend of levulinate esters and biodiesel would perform better over a wider range of temperatures than biodiesel," Mascal said.

Levulinate esters are nontoxic and are used as food additives, Mascal said.

Costs of the new process may be somewhat higher than for conventional biodiesel production, but should be offset by improved fuel yields and performance, he said.

The researchers are partnering with Bently Biofuels of Minden, Nev., to test the performance of levulinate/B100 blends.

(Photo: Jack Kelly Clark/UC Division of Agriculture and Natural Resource)

UC Davis

HOW YOU THINK ABOUT YOUR AGE MAY AFFECT HOW YOU AGE

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The saying "You're only as old as you feel" really seems to resonate with older adults, according to research from Purdue University.

"How old you are matters, but beyond that it's your interpretation that has far-reaching implications for the process of aging," said Markus H. Schafer, a doctoral student in sociology and gerontology who led the study. "So, if you feel old beyond your own chronological years you are probably going to experience a lot of the downsides that we associate with aging.

"But if you are older and maintain a sense of being younger, then that gives you an edge in maintaining a lot of the abilities you prize."

Schafer and co-author Tetyana P. Shippee, a Purdue graduate who is a research associate at Purdue's Center on Aging and the Life Course, compared people's chronological age and their subjective age to determine which one has a greater influence on cognitive abilities during older adulthood. Nearly 500 people ages 55-74 were surveyed about aging in 1995 and 2005 as part of the National Survey of Midlife Development in the United States.

In 1995, when people were asked what age do you feel most of the time, the majority identified with being 12 years younger than they actually were.

"We found that these people who felt young for their age were more likely to have greater confidence about their cognitive abilities a decade later," Schafer said. "Yes, chronological age was important, but the subjective age had a stronger effect.

"What we are not sure about is what comes first. Does a person's wellness and happiness affect their cognitive abilities or does a person's cognitive ability contribute to their sense of wellness. We are planning to address this in a future study."

Schafer also said that the current study's findings have both positive and negative implications.

"There is a tremendous emphasis on being youthful in our society and that can have a negative effect for people," Schafer said. "People want to feel younger, and so when they do inevitably age they can lose a lot of confidence in their cognitive abilities.

"But on the other hand, because there is such a desire in America to stay young, there may be benefits of trying to maintain a sense of youthfulness by keeping up with new trends and activities that feel invigorating. Learning new technologies is one way people can continue to improve their cognitive abilities. It will be interesting to see how, or if, these cultural norms shift as the Baby Boomer generation ages."

Other studies have shown that women are prone to aging stereotypes, so Schafer expected to see that women who felt older about themselves would have less confidence in their cognitive abilities.

"There is a slight difference between men and women, but it's not as pronounced as we expected," Schafer said. "This was surprising because of the emphasis on physical attractiveness and youth that is often disproportionately placed on women."

Schafer also is studying how stressful events, such as family members' health issues, affect aging, as well as how happiness and aging relate.

Purdue University

YOUR OLD SOFA - AND MUCH MORE - COULD BE COMPOSTED

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Polyurethane plastics used to make a host of products from furniture fillings to shoe soles, cable insulation and paints – and which can be difficult to recycle – could soon be degraded in compost heaps, thanks to a study at the University of Manchester.

Dr Geoff Robson and his team at the Faculty of Life Sciences have found that certain fungi can degrade the plastic in soil. Furthermore the rate of degradation increases when the volume of these fungi is increased or nutrients are added to the soil to boost the fungi’s activity.

They are now carrying out further studies to make sure the degradation of polyurethanes does not adversely affect the composting process or its products.

Dr Robson, whose Biotechnology and Biological Sciences Research Council (BBSRC) funded study is published in the Applied and Environmental Microbiology, said: “This is a significant finding. Polyurethanes are used to make many, many products and can take up a large amount of volume in landfill sites, which are rapidly running out of space. This makes it a major environmental pollutant.

“This study opens the possibility that fungi could be used to degrade these materials instead of dumping them into landfill sites.”

The team placed polyurethane pieces in soil containing fungi and bacteria. As the polyurethane, which is made from petroleum, degraded, the number of fungi increased as they digested the byproducts, showing that it was indeed the fungi that were breaking down the plastic.

Dr Robson added: “Fungi which naturally occur in soils have a remarkable capacity to degrade dead plants and animals, playing a pivotal and essential role in nutrient cycling in the environment. This study demonstrates some of these fungi also have the ability to degrade man-made polyurethanes.

“We demonstrated increased degradation of polyurethanes when buried in soil either by enhancing the activity of fungi already present by adding nutrients to the soil or by adding specific fungi to the soil that had previously been isolated from the surface of degrading polyurethane.”

The team is now investigating how best to apply their findings to polyurethane waste management. One possible method would be to spray fungi onto the polyurethane but another method would be to compost polyurethane along with other compostable materials – using already existing facilities.

Dr Robson, a biochemist and plant biologist who has studied fungi for many years, said: “Fungi are the classic underdogs. If we didn’t have fungi, we wouldn’t be here – we would be buried under mountains of stuff that they break down for us. They are also a treasure chest of pharmaceutical products, producing not just penicillin but also other antibiotics and immunosuppressant drugs. They are used to make arachadonic acid, the fatty acid essential for brain development in babies and used in baby milk formula, and their enzymes are used to turn milk into cheese, make bread dough rise better, clean our clothes in detergents and make fruit juice amongst many, many other applications.

“There is very little research on fungi compared to other microorganisms and only a fraction of them are actually known – around 20% have been identified.

“This latest finding just shows what amazing organisms they are.”

University of Manchester

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