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Comment by Dr. Krishna Kumari Challa on September 20, 2016 at 7:53am

Comment by Dr. Krishna Kumari Challa on September 20, 2016 at 6:43am

Filtering sea water in minutes!

• The technology is based on salt-attracting membranes and vaporising heat

• The membranes are made of cellulose acetate powder which is cheap to make

• Even remote communities could use the technique – with just membranes and fire.

Researchers at Alexandria University in Egypt have unveiled a cost-effective desalination technology which can filter highly salty water in minutes.

The technology is based on membranes containing cellulose acetate powder, produced in Egypt. The powder, in combination with other components, binds the salt particles as they pass through, making the technique useful for desalinating seawater. 

The membrane we fabricated can easily be made in any laboratory using cheap ingredients, which makes it an excellent option for developing countries.

The technology uses pervaporation, a technique by which the water is first filtered through the membrane to remove larger particles and then heated until it vaporises. The vapour is then condensed to get rid of small impurities, and clean water is collected.

This method can be used to desalinate water which contains different types of contamination, such as salt, sewage and dirt. This kind of water is difficult to clean quickly using existing procedures.

Desalination of simulated seawater by purge-air pervaporation using an innovative fabricated membrane

http://wst.iwaponline.com/content/72/5/785

Comment by Dr. Krishna Kumari Challa on September 17, 2016 at 7:20am

Comment by Dr. Krishna Kumari Challa on September 13, 2016 at 6:55am

After launching the world's first hack-free satellite,  China has tested its first quantum radar which could detect objects, including stealth aircraft, within the range of 100 kilometres.

The first Chinese quantum radar was developed by the Intelligent Perception Technology Laboratory of the 14th Institute of China Electronics Technology Group Corporation (CETC)

Quantum radar is a device that uses quantum entanglement photons to provide better detection capabilities than conventional radar systems.

The method would be useful for tracking targets with a low radar cross section, such as modern aircraft using stealth technology or targets employing active countermeasures to jam or baffle enemy radar.

The technology may also find use in biomedicine, since quantum radar requires lower energy and can be used to non-invasively probe for objects with low reflectivity, such as cancer cells.

Earlier, China launched the world s first quantum communications satellite, which uses quantum entanglement for cryptography.

Comment by Dr. Krishna Kumari Challa on September 2, 2016 at 8:01am

Comment by Dr. Krishna Kumari Challa on September 1, 2016 at 7:39am

Comment by Dr. Krishna Kumari Challa on August 31, 2016 at 9:29am

A possible four-phase coexistence in a single-component system

Explanation...

Japanese scientists have shown through simulations that four phases of a substance can coexist at thermal equilibrium, where all parts are at the same temperature and pressure—a situation that seemingly goes against the laws of thermodynamics. 

The findings, published in Nature Communications, not only deepen our basic understanding of phases of a substance existing in equilibrium, but may also be applied to the development of functional materials possessing phase-change properties.

 We constantly come across instances where various phases of a substance—such as gas, liquid, and solid—coexist with each other. For example, water (liquid) and ice (solid) coexist in shaved ice, a popular summer treat. Furthermore, the three phases of gas, liquid, and solid in water molecules coexist at a particular temperature and pressure known as the triple point. In a new study, the research group led by Professor Hajime Tanaka of the Institute of Industrial Science at the University of Tokyo has shown that four phases—three crystalline phases and one liquid phase—can coexist. These findings violate the Gibbs phase rule, which states that no more than three phases of a substance made from a single component can coexist at thermal equilibrium. 

the group systematically determined the particular temperature and pressure of the quadruple point where the four phases coexist, and defined the phase transition behavior—switching from one phase to another—around this point. This study may also prove useful in the development of functional phase-change materials as it demonstrates that multiple phase transformation can be induced near the quadruple point. 

Abstract:

For different phases to coexist in equilibrium at constant temperature T and pressure P, the condition of equal chemical potential μ must be satisfied. This condition dictates that, for a single-component system, the maximum number of phases that can coexist is three. Historically this is known as the Gibbs phase rule, and is one of the oldest and venerable rules of thermodynamics. In the paper published the researchers make use of the fact that, by varying model parameters, the Gibbs phase rule can be generalized so that four phases can coexist even in single-component systems. To systematically search for the quadruple point, they used a monoatomic system interacting with a Stillinger–Weber potential with variable tetrahedrality. Their study indicates that the quadruple point provides flexibility in controlling multiple equilibrium phases and may be realized in systems with tunable interactions, which are nowadays feasible in several soft matter systems such as patchy colloids.

http://www.nature.com/ncomms/2016/160825/ncomms12599/full/ncomms125...

Comment by Dr. Krishna Kumari Challa on August 25, 2016 at 8:45am

"Biological Pollution"

Most countries in the world have little capacity to deal effectively with invasive species, a study suggests.

The spread of non-native species threatens livelihoods and biodiversity, but the issue is worsened by global trade, travel and climate change.

Writing in Nature Communications journal, and international team forecast how the spread of species could change over the 21st Century.

They show that one-sixth of the world's land surface is vulnerable to invasion.

However, they predict that non-native plants, animals and microbes will increasingly threaten developing countries with some of the last remaining biodiversity hotspots, due to increased air travel and the expansion of agriculture.

This could endanger livelihoods and food security in fragile economies that are ill-prepared to deal with the expansion of invasive organisms.

Rampant globalisation will lead to invasions in countries with the least capability to deal with them. Low-income countries stand to lose a lot by having their natural resources sapped by invasive species.

Invasive species often travel as stowaways or contaminants in goods imported by planes and ships. They also arrive as exotic pets or plants that subsequently escape or are released deliberately into the wild.

This can pose challenges native species that have evolved over thousands of years to be well adapted to their ecosystems. Consequently, new arrivals can quickly change the nature of a whole region and often outcompete native organisms for resources and habitat.

Burmese pythons originally arrived in the US as exotic pets, but they escaped and quickly established themselves in the Florida Everglades, where they have contributed to a catastrophic decline in native mammals.

In Europe, forests and woods have been transformed by introduced diseases and pests such as Dutch elm disease and Ash dieback.

Biological invasions in the developing world so far have included influxes of Diamondback moths, which can devastate broccoli, cabbage and other crops; Panama disease, which wiped out banana plantations in central and south America; and prickly pear, which devastated grassland in Africa, leading to cattle being malnourished.

Comment by Dr. Krishna Kumari Challa on August 19, 2016 at 8:55am

The link between pollinator problems and neonicotinoids, a group of agricultural pesticides commonly associated with declines in honeybees, continues to build with two new studies published this week.

Within species, a population’s odds of going extinct increased with use of the pesticides, the research team worked on this  writes in the August 16 Nature Communications. That goes for both wild bees that forage on oilseed rape, and those that don’t — though populations of known foragers were three times as likely to disappear.

Taken together, the results add some long-term data to the idea that even though wild species aren’t pollinating neonicotinoid-doused crops, the effects of exposure may still appear at the regional and national level. 

Impacts of neonicotinoid use on long-term population changes in wild bees in England

http://www.nature.com/ncomms/2016/160816/ncomms12459/full/ncomms124...

Comment by Dr. Krishna Kumari Challa on August 19, 2016 at 7:58am

A black hole analogue, which traps sound instead of light, generates "Hawking radiation," a key prediction by the theoretical physicist. 

Stephen Hawking proposed in 1974 that quantum effects at the event horizon might cause black holes to be…not completely black. 

Recently scientists observed spontaneous Hawking radiation, stimulated by quantum vacuum fluctuations, emanating from an analogue black hole in an atomic Bose–Einstein condensate. Correlations are observed between the Hawking particles outside the black hole and the partner particles inside. These correlations indicate an approximately thermal distribution of Hawking radiation. They found that the high-energy pairs are entangled, while the low-energy pairs are not, within the reasonable assumption that excitations with different frequencies are not correlated. The entanglement verifies the quantum nature of the Hawking radiation. The results are consistent with a driven oscillation experiment and a numerical simulation.

http://www.nature.com/articles/nphys3863.epdf?referrer_access_token...

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