quinta-feira, 4 de dezembro de 2014

Superconducting coil to slash costs and improve efficiency of direct-drive wind turbines

 

 

Dr Shahriar Hossain is developing a wind turbine that uses a magnesium diboride supercondu...

Dr Shahriar Hossain is developing a wind turbine that uses a magnesium diboride superconducting coil

Conventional offshore wind turbines are expensive and complicated pieces of machinery – in a large part because of their complex and maintenance-intensive gearboxes. Dr Shahriar Hossain from the University of Wollongong (UOW) in Australia is looking to slash production costs and drastically improve efficiency replacing these gearboxes with a superconducting coil.

Wind turbine gearboxes connect the low-speed shaft, which is turned by the rotation of the blades, to the high-speed shaft that drives the generator, increasing the rotational speed of the low-speed shaft from around 30-60 rpm to the rotational speed required by the generator to produce electricity – which is usually around 1,000-1,800 rpm.

To avoid the cost, maintenance and efficiency-loss problems associated with the use of gear boxes, Dr Hossain, a materials scientist from the UOW's Institute of Superconducting and Electronic Materials with funding by the Australian Research Council in 2013 under the Discovery Early Career Researcher Award (DECRA) scheme, is developing a magnesium diboride superconducting coil made from magnesium and boron that he says is very cheap and easy to manufacture and would allow wind turbines to operate with no gearbox at all.

Unlike a conduction loop made of conventional copper wire that loses about seven to 10 percent of energy due to resistance when an electric current is sent into it, a superconducting loop would have no loss of energy as it has no electrical resistance. This would allow the current to circulate indefinitely, even after the power is cut off.

When we reached out to Dr Hossain to ask about the problems surrounding the low temperatures required for the superconductors to work, he admitted this is the most challenging part of developing the system around the magnesium diboride superconducting coil.

To address the problem he plans to use off-the-shelf cryocoolers to cool the rotating components of the system in a two-stage process. The first crycooler will drop the temperature to -218° C (-360° F), while the second will then lower it further to -253° C (-424° F). Dr Hossain says that in comparison to well-established niobium-based superconductors, his magnesium diboride-based superconductors have achieved very high critical current density.

Despite this two cryocooler arrangement, Dr Hossain says it will still be cheaper than using high temperature superconductors (HTS), which can exhibit superconductivity at temperatures as high as -135° C (-211° F), but cost around AUD$25 (US$21) a meter. Dr Hossain's US industry partner, Hyper Tech Research, predicts that magnesium diboride coil will cost just $1 (US$0.85) a meter to manufacture by 2015.

Additionally, unlike niobium-based low temperature superconductors (LTS) that require increasingly pricey liquid helium to operate, Dr Hossain says the cryocooler system will run with ambient temperature helium gas supplied by compressors and entering into the rotor and returning through a rotary coupling in a closed loop.

Dr Hossain says that 10 MW-class wind turbines will require up to 200 km (124 mi) of superconducting coil to generate electricity, with each HTS-based coil costing between AUD$3 to $5 million (US$2.5 to $2.4 million) to manufacture. However, he claims that the same length of magnesium diboride superconducting coil would cost just AUD$180,000 (US$153,000), with that figure expected to drop significantly.

"Australia desperately needs sustainable energy sources," says Dr Hossain. "Wind is cheap, clean and we can get it day and night and on rainy and sunny days. And considering Australia has more than 35,000 km of coastline, there is ample room for offshore wind farms. With industry support, we could install superconducting offshore wind turbines off the coast of Australia in five years, no problem."

Source: University of Wollongong

 

New model to detect aggressive driving

 

 

Boosting new behavior patterns could prevent a significant percentage of accidents.

Researchers from the UPM have developed a system capable of detecting patterns of reckless driving behavior with non intrusive methods for the driver.

A group of researchers from the High School of Telecommunications Engineering of the Universidad Politécnica de Madrid (UPM) has shown that is possible to detect an aggressive driving behavior by just monitoring external driving signals such as the speed or acceleration, since the aggressiveness works as a linear filter on these signals. This model was validated with empirical data under real driving situations with rates exceeding 92%.

Traffic accidents annually produce 1.3 million fatalities and 50 million injuries worldwide. They are currently the main cause of death among young adults between 15-29 years old. Apart from these deaths, traffic accidents cause high economic cost due to property damage and medical expenses, amongst others, estimated at around half a billion Euros per year. The 70% of these accidents are related to human factors and reckless driving which is the result of an excessive or inappropriate speed.

Boosting new behavior patterns could prevent a significant percentage of accidents. One way to promote these behavior changes of drivers it can be the monitoring and characterization of their driving in order to detect inappropriate driving situations and early warn at risk of accident.

The early research works in this field were mainly based on the characterization through intrusive methods by monitoring physiological signals such as heart rate, breathing and stress level. These methods, though effective, are less appropriate because can produce discomfort to the driver and represent an additional cause of distraction.

The question is, can we efficiently characterize the driving through non intrusive methods and that are not perceived by the driver? A group of researchers for the Applied Mathematics for Information Technology and Communications Department of the High School of Telecommunications Engineering of UM has found the answer. Thanks to this research, they have shown that is possible to detect a reckless driving behavior by just monitoring driving external signals, such as velocity and acceleration.

The key is that aggressiveness performs like a linear filter on these signals: scaling its probability distribution and modifying its average value, standard deviation and dynamic range.

The model was empirically verified under real driving situations at UPM facilities. They tested its validity and its generality for diverse driving signals, different drivers and types of roads. The results showed a success rate of 92% for detecting reckless driving behavior from driving signals. In the future, this real time reckless driving system for early detection will be integrated into smartphones, significantly contributing to increase safety on the roads.

People conceived during Dutch famine have altered regulation of growth genes

 

 

December 3, 2014

Columbia University's Mailman School of Public Health

Individuals conceived in the severe Dutch Famine may have adjusted to this horrendous period of World War II by making adaptations to how active their DNA is. Genes involved in growth and development were differentially regulated, according to researchers. Extensive research on the DNA of these children shows that the regulatory systems of their growth genes were altered, which may also explain why they may be at higher risk for metabolic disease in later life.


Individuals conceived in the severe Dutch Famine, also called the Hunger Winter, may have adjusted to this horrendous period of World War II by making adaptations to how active their DNA is. Genes involved in growth and development were differentially regulated, according to researchers at the Leiden University Medical Center, Harvard University, and Columbia University's Mailman School of Public Health. Findings are published in the journal Nature Communications.

During the winter of 1944-1945 the Western part of The Netherlands was struck by a severe 6-month famine. During this Hunger Winter the available rations provided as low as a quarter of the daily energy requirements. Children conceived -- but not born -- during the famine were delivered with a normal birth weight. Extensive research on the DNA of these Hunger Winter children shows that the regulatory systems of their growth genes were altered, which may also explain why they appear to be at higher risk for metabolic disease in later life.

Decades later growth genes seemed different

"The different setting of the growth genes may have helped the Hunger Winter children to withstand the Famine conditions as compared with their unexposed siblings, but these changes may likewise be unfavorable for their metabolism as adults," said Leiden University principal investigator Dr. Bas Heijmans. For example, the altered settings were associated with LDL cholesterol at age 60, according to the authors.

The research team in Leiden compared the DNA of the Hunger Winter children, now aged 60, at 1.2 million CpG methylation sites comparing them with same-sex siblings not exposed to famine. They were able to see how the genes were differentially regulated in the Hunger Winter children, as compared with their siblings with a similar genetic and familial background. Groups of genes involved in growth and development showed a different gene activity setting. The Hunger Winter children were all approximately 60 years of age when they gave blood for DNA research. It was at this point in time that their growth genes seem altered for life.

"The potential for a gene to become active is mainly determined in the crucial weeks after fertilization. This master regulatory system that determines which genes are on and which are off is called epigenetics and can be compared to a sound technician making adjustments during a recording to get that perfect sound. Environmental factors during development can make a lasting imprint on this system," noted Dr. Heijmans.

The authors point out that a wealth of past epidemiological studies suggests that early development is important for later health. "Thanks to the willingness of the Hunger Winter children and their families to contribute to our studies, we can pin- point which phases of development are especially sensitive to the environment. We are currently extending our inquiries not only to those conceived during the famine, but also to those exposed during other gestation periods. A lot of important things are happening in the womb about which we know quite little in humans," says co-author Dr. Elmar W. Tobi.

"These findings are exciting and provide tremendous opportunities for epidemiologists," said L.H. Lumey, MD, associate professor of Epidemiology at Columbia University's Mailman School of Public Health and senior author who collected the analyzed blood samples. "Looking at the human genome we see systematic changes in gene regulation during early human development in response to the environment. The epigenetic revolution has given us the tools to investigate these changes and look at the impact for later life."


Story Source:

The above story is based on materials provided by Columbia University's Mailman School of Public Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. Elmar W. Tobi, Jelle J. Goeman, Ramin Monajemi, Hongcang Gu, Hein Putter, Yanju Zhang, Roderick C. Slieker, Arthur P. Stok, Peter E. Thijssen, Fabian Müller, Erik W. van Zwet, Christoph Bock, Alexander Meissner, L. H. Lumey, P. Eline Slagboom, Bastiaan T. Heijmans. DNA methylation signatures link prenatal famine exposure to growth and metabolism. Nature Communications, 2014; 5: 5592 DOI: 10.1038/ncomms6592

 

Nutrition, safety key to consumer acceptance of nanotech

 

Tue, 12/02/2014 - 10:08am

Matt Shipman, News Services, North Carolina State Univ.

New research from North Carolina State Univ. and the Univ. of Minnesota shows the majority of consumers will accept the presence of nanotechnology or genetic modification (GM) technology in foods—but only if the technology enhances the nutrition or improves the safety of the food.

“In general, people are willing to pay more to avoid GM or nanotech in foods, and people were more averse to GM tech than to nanotech,” says Dr. Jennifer Kuzma, senior author of a paper on the research and co-director of the Genetic Engineering in Society Center at NC State. “However, it’s not really that simple. There were some qualifiers, indicating that many people would be willing to buy GM or nanotech in foods if there were health or safety benefits.”

The researchers conducted a nationally representative survey of 1,117 U.S. consumers. Participants were asked to answer an array of questions that explored their willingness to purchase foods that contained GM tech and foods that contained nanotech. The questions also explored the price of the various foods and whether participants would buy foods that contained nanotech or GM tech if the foods had enhanced nutrition, improved taste, improved food safety or if the production of the food had environmental benefits.

The researchers found that survey participants could be broken into four groups.

Eighteen percent of participants belonged to a group labeled the “new technology rejecters,” which would not by GM or nanotech foods under any circumstances. Nineteen percent of participants belonged to a group labeled the “technology averse,” which would buy GM or nanotech foods only if those products conveyed food safety benefits. Twenty-three percent of participants were “price oriented,” basing their shopping decisions primarily on the cost of the food—regardless of the presence of GM or nanotech. And 40% of participants were “benefit oriented,” meaning they would buy GM or nanotech foods if the foods had enhanced nutrition or food safety.

“This tells us that GM or nanotech food products have greater potential to be viable in the marketplace if companies focus on developing products that have safety and nutrition benefits—because a majority of consumers would be willing to buy those products,” Kuzma says.

“From a policy standpoint, it also argues that GM and nanotech foods should be labeled, so that the technology rejecters can avoid them,” Kuzma adds.

The paper is published online in the Journal of Agricultural Economics.

Source: North Carolina State Univ.

6 Ways Your Bedroom May Be Sabotaging Your Sleep - republishing -

 

How to make your bedroom more conducive to sleep

Let’s face it: we all know that sometimes, getting ourselves (or our kids) into bed is only half the struggle when it comes to falling asleep. Lying there, or tossing and turning as the minutes turn into hours while sleep continues to eludes us can be really frustrating, and no help when the alarm goes off the next morning and we can barely get going.

There can be lots of reasons why people have difficulty falling or staying asleep, and I’ve addressed many of them in previous posts as well as in my book

One of them, often overlooked, is the quality of the sleep environment itself. Namely: how conducive your bedroom is to falling asleep.

Here are a number of things to look for in your, or your child’s bedroom, which may be interfering with your ability to fall asleep at night:

  1. Too much light. Bright light, especially in the evening, has a very powerful awakening effect on the brain.

  2. Make sure the bedroom lights are dim, or better yet turned off completely. If you read before going to bed, use a low-wattage lamp. If a night light is needed, use the lowest wattage you can find (no more than 7 watts) and make sure that the light it casts does not shine directly on the bed. In the summer months, when trying to go to sleep (or to put younger kids to bed) before the sun has set, consider using light-blocking shades or curtains.

  3. Too many distractions. Televisions , computers, iPads, video games are problematic not only because of the light they case, but because of their content, which can rile up the brain just as you’re trying to calm it down.  And while falling asleep to soothing music can be very helpful to some, not all music is soothing. I’ve met teens with difficulty initiating sleep who never made the connection between the heavy metal they listened to in bed at night and why it was taking them so long to fall asleep.

  4. Pets. Whether it’s a dog who snuggles up and leaves you little room to stretch out, or a cat that’s constantly moving about, your pet may be causing more of your sleep problems than you realize. If you’re not convinced, consider videotaping the bed one night and watching what happened over the course of the night.

  5. Too much stress. Taking computers, homework, or work into bed is an especially big no-no, because it can generate stress that lingers even after the task is complete, and the computer turned off and the notebooks put away. It’s important to keep the bed for sleep (and sex, when appropriate), and not to allow negative associations to develop between the bed and unpleasant or stress-generating tasks which can then interfere with sleep.

  6. Clocks. Even though the stress they produce is a direct continuation of point #4, they bear special mention. Nothing is more anxiety-producing than watching the minutes tick by as you lie in bed and can’t fall asleep. “Oh no, it’s been half an hour, and I’m still awake… Now it’s been thirty-five minutes and I still haven’t fallen asleep.” Most of us need an alarm to wake up in the morning, but that doesn’t mean that the clock has to face the bed. Move it out of arms-reach and out of sight. For example: put the clock on a dresser across the room and facing the wall. That will make it much less tempting to look at.

  7. Noise.  Thin walls, snoring bed partners, or family members watching TV in the den can all make it harder to fall asleep. Sometimes this is easy to fix, but not always. If that’s the case, consider foam earplugs, or a fan or white noise machine to mask the sound

Good luck, and good night!

Dennis Rosen, M.D.

Help your child get a great night's sleep with the new book:

Successful Sleep Strategies for Kids (a Harvard Medical School Guide)

New molecules to burst malaria's bubble

 

 

December 3, 2014

Australian National University

Scientists have released details of a raft of new chemicals with potent anti-malarial properties which could open the way to new drugs to fight malaria. Over 200 million people contract malaria each year, and the parasite that causes the disease has become resistant to most of the drugs currently available. The papers show the malaria parasite has real Achilles heel, and we now have range of new ways to attack it.


Dr Natalie Spillman.

Scientists have released details of a raft of new chemicals with potent anti-malarial properties which could open the way to new drugs to fight the disease.

A new paper in PNAS is the third published recently by a group at the Australian National University (ANU). The group has collaborated with scientists from around the globe to uncover potential ammunition in the fight against malaria.

Over 200 million people contract malaria each year, and the parasite that causes the disease has become resistant to most of the drugs currently available.

"The series of papers shows that the malaria parasite has a real Achilles heel, and describe a range of new ways to attack it," said Professor Kiaran Kirk, Dean of the College of Medicine, Biology and Environment and one of the scientists involved in the project.

Dr Natalie Spillman, from the Research School of Biology at ANU studied the mechanism by which the parasites are killed.

"The new molecules block a molecular salt pump at the surface of the parasite, causing it to fill up with salt," Dr Spillman said

"This has the effect of drawing water into the parasite, causing it to swell uncontrollably and burst."

Although the process of developing the new compounds into clinical drugs is complex and lengthy, Professor Kirk is optimistic the findings will lead to new treatments.

"It's very early days, but these pump-blocking compounds have some of the most promising anti-malarial potential we've seen," he says.

Aspects of the work were carried out with groups at Griffith University, Monash University and the Menzies School of Health Research in Darwin.

"This is a good example of a long-term, international drug development program in which Australian groups have played a key role," he said.


Story Source:

The above story is based on materials provided by Australian National University. Note: Materials may be edited for content and length.


Journal Reference:

  1. María Belén Jiménez-Díaz, Daniel Ebert, Yandira Salinas, Anupam Pradhan, Adele M. Lehane, Marie-Eve Myrand-Lapierre, Kathleen G. O’Loughlin, David M. Shackleford, Mariana Justino de Almeida, Angela K. Carrillo, Julie A. Clark, Adelaide S. M. Dennis, Jonathon Diep, Xiaoyan Deng, Sandra Duffy, Aaron N. Endsley, Greg Fedewa, W. Armand Guiguemde, María G. Gómez, Gloria Holbrook, Jeremy Horst, Charles C. Kim, Jian Liu, Marcus C. S. Lee, Amy Matheny, María Santos Martínez, Gregory Miller, Ane Rodríguez-Alejandre, Laura Sanz, Martina Sigal, Natalie J. Spillman, Philip D. Stein, Zheng Wang, Fangyi Zhu, David Waterson, Spencer Knapp, Anang Shelat, Vicky M. Avery, David A. Fidock, Francisco-Javier Gamo, Susan A. Charman, Jon C. Mirsalis, Hongshen Ma, Santiago Ferrer, Kiaran Kirk, Iñigo Angulo-Barturen, Dennis E. Kyle, Joseph L. DeRisi, David M. Floyd, R. Kiplin Guy. ( )-SJ733, a clinical candidate for malaria that acts through ATP4 to induce rapid host-mediated clearance ofPlasmodium. Proceedings of the National Academy of Sciences, 2014; 201414221 DOI: 10.1073/pnas.1414221111

 

Nanotube film could replace defective retinas

 

Damaged or defective retinas may someday be replaced by a nanotube film that transforms li...

Damaged or defective retinas may someday be replaced by a nanotube film that transforms light into electrical signals and thereby restores regular vision (Photo: Shutterstock)

A promising new study suggests that a wireless, light-sensitive, and flexible film could potentially form part of a prosthetic device to replace damaged or defective retinas. The film both absorbs light and stimulates neurons without being connected to any wires or external power sources, standing it apart from silicon-based devices used for the same purpose. It has so far been tested only on light-insensitive retinas from embryonic chicks, but the researchers hope to see the pioneering work soon reach real-world human application.

Some neurons are genetically-predisposed to be sensitive to light. An emerging field called optogenetics uses light to stimulate and control those neurons, with applications not only in vision but also in gene therapy, brain mapping, reducing pain sensitivity, treatment of neurological disorders such as epilepsy and Parkinson's disease, and even mind control.

The researchers sought to develop an optogenetics approach to restoring vision. They combined semiconductor nanorods and carbon nanotube film and found that the resultant system stimulated neurons in light-insensitive embryonic chicks at day 14 of their development when illuminated with violet light for 100 ms.

A carbon nanotube-semiconductor nanocrystal film attached to the retina stimulates neurons...

Most previously-tested artificial vision technologies are silicon based, with rigid, non-transparent photoconductive chips implanted (often invasively and with great complexity) into the subject and connected to an external power source. These older systems also suffer from long-term stability issues and low spatial resolution, the researchers note.

"We hope our carbon nanotube and semiconductor nanorod film will serve as a compact replacement for damaged retinas," said lead researcher Yael Hanein. His colleague Lilach Bareket cautions, however, that scientists are "still far away from actually replacing the damaged retina."

If the technology does prove viable for use in humans, we could see it applied in treatment of age-related macular degeneration, which currently affects as many as 15 million Americans, and in other retina-based vision problems – including many forms of blindness.

The research was conducted by an international team spread across Tel Aviv University, the Hebrew University of Jerusalem, and Newcastle University. A paper describing the work has been published in the journal Nano Letters.

Sources: The Hebrew University of Jerusalem, Tel Aviv University

 

Novel approach to treating asthma: Neutralize the trigger

 

Current asthma treatments can alleviate wheezing, coughing and other symptoms felt by millions of Americans every year, but they don't get to the root cause of the condition. Now, for the first time, scientists are reporting a new approach to defeating asthma by targeting the trigger -- the allergen -- before it can spark an attack. They describe their new compound, which they tested on rats, in ACS' Journal of Medicinal Chemistry.

Clive Robinson and colleagues explain that to prevent many health problems, the ideal approach to treatment or prevention involves getting to the cause of a condition and targeting it directly. Asthma, which occurs when the immune system goes into overdrive affecting the airway in response to an otherwise harmless substance, has posed a challenge to this model. That's because it can be set off by different allergens or irritants. But recent studies suggest that the picture might not be as complicated as previously thought. Scientists have found that dust mites are one of the most important triggers of allergic asthma. So Robinson's team wanted to find a way to neutralize mite allergens.

The researchers identified a compound that binds to a major dust mite allergen and turned it into an inhalable powder. They tested it on rats and found that it significantly dampened the animals' immune response when they were exposed to a variety of allergens. This compound and other similar inhibitors could hail a new direction in asthma treatment, say the researchers.

The authors acknowledge funding from the Wellcome Trust.


Story Source:

The above story is based on materials provided by American Chemical Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Gary K. Newton, Trevor R. Perrior, Kerry Jenkins, Meriel R. Major, Rebekah E. Key, Mark R. Stewart, Stuart Firth-Clark, Steven M. Lloyd, Jihui Zhang, Nicola J. Francis-Newton, Jonathan P. Richardson, Jie Chen, Pei Lai, David R. Garrod, Clive Robinson. The Discovery of Potent, Selective, and Reversible Inhibitors of the House Dust Mite Peptidase Allergen Der p 1: An Innovative Approach to the Treatment of Allergic Asthma. Journal of Medicinal Chemistry, 2014; 57 (22): 9447 DOI: 10.1021/jm501102h