Monday, March 22, 2010

A HUGE STEP TOWARD MASS PRODUCTION OF COVETED FORM OF CARBON

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Scientists have leaped over a major hurdle in efforts to begin commercial production of a form of carbon that could rival silicon in its potential for revolutionizing electronics devices ranging from supercomputers to cell phones. Called graphene, the material consists of a layer of graphite 50,000 times thinner than a human hair with unique electronic properties. Their study appears in ACS' Nano Letters, a monthly journal.

Victor Aristov and colleagues indicate that graphene has the potential to replace silicon in high-speed computer processors and other devices. Standing in the way, however, are today's cumbersome, expensive production methods, which result in poor-quality graphene and are not practical for industrial scale applications.

Aristov and colleagues report that they have developed "a very simple procedure for making graphene on the cheap." They describe growing high-quality graphene on the surface of commercially available silicon carbide wafers to produce material with excellent electronic properties. It "represents a huge step toward technological application of this material as the synthesis is compatible with industrial mass production," their report notes.

(Photo: Wikimedia Commons)

ACS' Nano Letters

WORLD CRUDE OIL PRODUCTION MAY PEAK A DECADE EARLIER THAN SOME PREDICT

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In a finding that may speed efforts to conserve oil and intensify the search for alternative fuel sources, scientists in Kuwait predict that world conventional crude oil production will peak in 2014 — almost a decade earlier than some other predictions. Their study is in ACS' Energy & Fuels, a bi-monthly journal.

Ibrahim Nashawi and colleagues point out that rapid growth in global oil consumption has sparked a growing interest in predicting "peak oil" — the point where oil production reaches a maximum and then declines. Scientists have developed several models to forecast this point, and some put the date at 2020 or later. One of the most famous forecast models, called the Hubbert model, accurately predicted that oil production would peak in the United States in 1970. The model has since gained in popularity and has been used to forecast oil production worldwide. However, recent studies show that the model is insufficient to account for more complex oil production cycles of some countries. Those cycles can be heavily influenced by technology changes, politics, and other factors, the scientists say.

The new study describe development of a new version of the Hubbert model that accounts for these individual production trends to provide a more realistic and accurate oil production forecast. Using the new model, the scientists evaluated the oil production trends of 47 major oil-producing countries, which supply most of the world's conventional crude oil. They estimated that worldwide conventional crude oil production will peak in 2014, years earlier than anticipated. The scientists also showed that the world's oil reserves are being depleted at a rate of 2.1 percent a year. The new model could help inform energy-related decisions and public policy debate, they suggest.

(Photo: iStock)

ACS' Energy & Fuels

SCIENTISTS SOLVE PUZZLE OF CHICKENS THAT ARE HALF MALE AND HALF FEMALE

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A puzzle that has baffled scientists for centuries – why some birds appear to be male on one side of the body and female on the other – has been solved by researchers.

The research, which involved studying rare naturally occurring chickens with white (male) plumage on one side and brown (female) plumage on the other, sheds new light on the sexual development of birds.

It was previously thought that sex chromosomes in birds control whether a testis or ovary forms, with sexual traits then being determined by hormones.

The researchers, however, identified differences between male and female cells that control the development of sexual traits. The scientists have named the phenomenon, cell autonomous sex identity (CASI).

The study from The Roslin Institute at the University of Edinburgh, which receives key funding from the Biotechnology and Biological Sciences Research Council, is published in the journal Nature.

The findings, which are scientifically revolutionary in the field, may also be relevant to why males and females differ in behaviour and in susceptibility to disease.

They could also lead to improvements in poultry production - identification of some of the molecular differences between male and female cells should lead to better tests for sexing embryos prior to hatch. It might even be possible to devise ways of obtaining the growth characteristics of male birds in females, with improvements in feed efficiency and productivity that could contribute to future food security.

Dr Michael Clinton, who led the study, said: "This research has completely overturned what we previously thought about how sexual characteristics were determined in birds. We now believe that the major factors determining sexual development are built into male and female cells and derive from basic differences in how sex chromosome genes are expressed. Our study opens a new avenue for our understanding of sexual development in birds.

"It also means we must now reassess how this developmental process occurs in other organisms. There is already some evidence that organs such as the heart and brain are intrinsically different in males and females and birds may provide a model for understanding the molecular basis for these gender differences."

The group will now study the molecular mechanisms underlying the differences between male and female cells with a £800,000 grant from the Biotechnology and Biological Sciences Research Council (BBSRC), the UK's leading biosciences agency.

University of Edinburgh

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