Greater desertification control using sand trap simulations

A new simulation will help improve artificial sand-control measures designed to help combat desertification

2013-09-27

(Press-News.org) In the fight against desertification, so-called straw checkerboard barriers (SCB) play a significant role. SCB consists of half -exposed criss-crossing rows of straws of wheat, rice, reeds, and other plants. The trouble is that our understanding of the laws governing wind-sand movement in SCB and their surrounding area is insufficient. Now, Ning Huang and colleagues from Lanzhou University in China have performed a numerical simulation of the sand movement inside the SCB, described in a paper just published in EPJ E. China is particularly affected by desertification, which affects 18 percent of its territory. The results will help us to understand sand fixation mechanisms that are relevant for sandstorm and land-desertification control.

The authors relied on a simulation of large eddies, which are circulations around an obstruction such as the SCB walls, to study the turbulence stress. They also used a discrete particle-tracing method to numerically simulate the wind -sand movement inside the SCB. Specifically, they described the sand as a gas, using equations to describe their space-averaged hydrodynamics. They also analysed in detail the movement characteristics of sand particles, the transverse velocities of sand particles and wind-sand flow within the SCB using a model taking into consideration the coupling effects of wind field and sand particles.

Huang and colleagues found that the SCB contributed to a decrease in the sand transport rate in its interior, thus helping the sand fixation. What is more, as the transverse distance increases, the strength of wind-sand flow eddies decreases. Meanwhile, the sand accumulates near the interior walls of the SCB. Finally, as the number of SCBs increases, the wind is less able to transport sand.

Future studies will be designed to optimise SCB design, based on the authors' theoretical analysis. These findings could also be used to study the evolution to sand dunes.

### References N. Huang, X. Xia, D. Tong (2013), Numerical Simulation of Wind-sand Movement in Straw Checkerboard Barriers, European Physical Journal E,DOI 10.1140/epje/i2013-13099-6

For more information visit: http://www.epj.org

The full-text article is available to journalists on request

ELSE PRESS RELEASES FROM THIS DATE:

Study reveals differences in post-operative complications

2013-09-27

Older black and Hispanic patients have a greater risk than white patients of developing complications following surgery, a difference that can be explained by a patients' gender and pre-existing medical conditions. These findings, which are published today in the Journal of the American Geriatrics Society (JAGS), indicate that efforts to carefully evaluate risk factors prior to surgery need more attention, particularly for older minority patients. Research has shown that minority groups tend to develop complications following surgery more often than whites. Investigators ...

Baculovirus-recognizing human cell receptor identified for the first time

2013-09-27

The receptor used by baculovirus to enter and interact with human cells has been identified. This syndecan-1 receptor was identified for the first time in a recent collaborative study carried out by the University of Eastern Finland and the University of Jyväskylä in Finland. The findings increase our understanding of the strategies by which the virus causes infection in cells and further facilitates the development of baculovirus for applications of gene transfer. According to the researchers, the identification of the syndecan-1 receptor helps in understanding the ways ...

CNIO scientists reduce progression of one of the most aggressive skin cancers in mice

2013-09-27

The c-Fos oncogene has traditionally been linked to cellular activities related to cancer, such as cell division, differentiation—conversion from one cell type to another—or survival. Any alteration of these activities can set off the development of tumours, which has made c-Fos an important target for the understanding and treatment of cancer. A study led by Erwin Wagner, head of the F-BBVA-CNIO Cancer Cell Biology Programme and of the Genes, Development and Disease Group, has revealed a novel mechanism in which c-Fos is able to promote skin cancer: an increase in c-Fos ...

Genes against parasites

2013-09-27

Every year, millions of cattle die of trypanosomosis. The UN and the International Livestock Research Institute list trypanosomosis among the ten diseases of cattle with the greatest impact on the poor. In Africa the disease is known as "Nagana", which translates literally as "being in low or depressed spirits". The disease is caused by a parasite that enters the animals' blood as a result of the bite of the Tsetse fly. Surprisingly, one West-African dwarf cattle breed, the Baoulé, seems less affected by trypanosomosis than others. When they are infected, Baoulé cattle ...

CWRU philosopher examines the hypothesis vs. exploratory funding divide

2013-09-27

A Case Western Reserve University professor wondered why some types of research were more apt to secure federal grants, while others -- especially exploratory science -- often didn't. Using the National Institutes of Health (NIH) as a case study, Assistant Philosophy Professor Chris Haufe concluded that hypothesis-based research has the edge over discovery research for several reasons that he explains in a new paper. Haufe discusses the NIH's peer-reviewed grant process in his Studies in History and Philosophy of Science journal article, "Why do funding agencies favor ...

Study finds socio-economic status impact mortality rates for certain stroke in US

2013-09-27

TORONTO, Sept. 27, 2013—Americans in the highest socio-economic groups have a 13 per cent greater chance of surviving a kind of stroke known as a subarachnoid hemorrhage than those in the lowest socio-economic groups, a new study has found. However, social and economic status have no bearing on mortality rates for subarachnoid hemorrhages, or SAH, in Canada, according to the study led by Dr. Loch Macdonald, a neurosurgeon at St. Michael's Hospital in Toronto. "The findings suggest Canada's universal, publicly funded health insurance coverage may play a role in improving ...

Mobile tech and talk therapies strike at the moment binge eating urges do

2013-09-27

PHILADELPHIA (September 27, 2013) -- Two new treatment methods under investigation at Drexel University aim to help people reduce binge-eating behavior. A smartphone app in development will track users' individual patterns of eating and binge eating behavior and alert them at times when they are at risk for binge behaviors, among a comprehensive suite of other features. Another treatment is a new, evidence-based approach to small-group behavioral therapy that will equip patients with psychological tools that may help them adhere to, and benefit from, standard treatments ...

Latest research suggests moderate coffee consumption is not associated with increased CVD risk

2013-09-27

Coffee is one of the most extensively researched components in the diet. New studies are regularly being added to the already large body of scientific research, which overall suggests that moderate habitual coffee consumption is not associated with detrimental effects on cardiovascular health Among recent studies, a new review paper1 highlights that for most healthy people, moderate coffee consumption is unlikely to adversely affect cardiovascular health. Furthermore a new paper2 concluded that higher green tea and coffee consumption is inversely associated with risk ...

Over the limit: Size, shape and color of wine glass affect how much you pour

2013-09-27

Pouring a glass of wine is rarely an exact measurement, especially in a social setting. While most people think of a glass as one serving, in reality it could be closer to two or three. Researchers at Iowa State and Cornell universities discovered just how much one pours is influenced by a variety of environmental factors and could have serious consequences when it comes to overconsumption. In the study, published in the journal Substance Use and Misuse, participants were asked to pour what they considered a normal drink using different types of glasses in various settings. ...

Early intervention by infectious diseases specialists saves lives, reduces costs

2013-09-27

WASHINGTON, Sept. 26, 2013 – In a first-of-its-kind study to evaluate the impact of a medical specialty on patient outcomes, researchers found that hospitalized patients with severe infections such as meningitis and Clostridium difficile (C. diff.) are significantly less likely to die if they receive care from an infectious diseases specialist. The study, which analyzed nearly 130,000 Medicare patient cases, is now available online and will be published in the December 15 issue of Clinical Infectious Diseases. According to the data, researchers at Avalere Health and the ...

Pollen counts can be predicted by machine learning models using meteorological data with more than 80% accuracy even a week ahead, for both grass and birch tree pollen, which could be key in effective

Rewriting our understanding of early hominin dispersal to Eurasia

Rising simultaneous wildfire risk compromises international firefighting efforts

Honey bee "dance floors" can be accurately located with a new method, mapping where in the hive forager bees perform waggle dances to signal the location of pollen and nectar for their nestmates

Greater desertification control using sand trap simulations

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: