Knowledge Update

New York, June 27 (IANS) Ever struggled with a shampoo bottle in trying to get the last drop out or the last bit of a hand wash, dish wash or laundry detergent? Worry not as researchers, including one of Indian-origin, have found a way to create the perfect texture inside plastic bottles to let soap products flow out freely. The new technology involves lining a plastic bottle with microscopic "y-shaped" structures that cradle the droplets of soap aloft above tiny air pockets so that the soap never actually touches the inside of the bottle. "Manufacturers are really interested in this because they make billions of bottles that end up in the garbage with product still in them," said Bharat Bhushan, Professor from Ohio State University. The "y" structures are built up using spray-coating a small amount of solvent and ultra-fine silica nanoparticles onto the inside of bottles. Mixing the silica and solvent to the surface of the polypropylene -- the common plastics used to package foodstuffs and household goods -- softened it just enough, so that when the plastic re-hardened, the silica got embedded in the surface. The structures are only a few micrometers -- millionths of a meter-high -- and covered in even smaller branchlike projections. The main branches of the "y" overhang the plastic surface at an angle less than 90 degrees -- steep enough that water, oils and even surfactant can't physically sustain a droplet shape that would fall in between the branches and touch the plastic. Surfactants -- the organic molecules that make soap "soapy"-- have a very low surface tension and stick to plastic easily. "It was an extra challenge for us to make a surface that could repel surfactant as the plastic bottles end up with air pockets underneath that gives them a liquid repellency," explained Philip Brown, post-doctoral Student at Ohio State. But, "we embedded a hard material directly into the polymer surface, so we know it's durable," Brown added in a paper published in the journal Philosophical Transactions of the Royal Society. The researchers further hope to license the coating technique to manufacturers -- not just for shampoo bottles, but for other plastic products that have to stay clean, such as biomedical devices or catheters. ​

​Beijing, June 26 (IANS) China will send its second orbiting space lab Tiangong-2 into space in mid September, said a senior official with the country's manned space programme.

The Shenzhou-11 manned spacecraft will be launched in mid September and its re-entry module will return in November, said Wu Ping, deputy director of the manned space engineering office, at a press conference on Saturday after the successful launch of the Long March-7, a new generation carrier rocket, at Wenchang, Hainan province.

As part of the country's space lab programme, the Shenzhou-11 spacecraft will carry two astronauts on board and dock with Tiangong-2.

The two astronauts have been chosen and currently under intense training, Wu said.

The Tiangong-2 and Shenzhou-11 will be carried by Long March-2F carrier rocket, she said.

In April 2017, the country's first cargo spaceship, Tianzhou-1, will be launched and carried by the Long March-7, Wu said.

"With the improvement of the rocket's technological performance, the Long March-7 will step by step replace the current carrier rockets and become the main carrier for space launches," she added.​

Kuala Lumpur, June 26 (IANS) Dried sewage sludge could be recycled by adding it to cement to make concrete, researchers in Malaysia have discovered.

Disposing sludge left over from treating sewage water is a major challenge for wastewater plants.

Meanwhile, the construction sector seeks economic and ecological cement replacement materials in order to meet an increasing demand for concrete.

Researchers from Universiti Teknologi MARA investigated the potential to replace various quantities of cement with processed sewage sludge to create a concrete mixture.

The researchers first produced domestic waste sludge powder (DWSP). They dried and burnt wet sludge cake to remove moisture, and then ground and sieved the dried sludge cake to make the sludge powder.

Using varying proportions of the powder, ranging from three-fifteen per cent, the researchers mixed the material with cement to produce normal strength and two higher strength grades of concrete.

They then compared the domestic waste sludge powder concrete mixture of each proportion with normal concrete in terms of their compressive strength, water absorption, water permeability and permeability to salt.

Overall, the researchers found that while domestic waste sludge powder has a potential role in the manufacture of concrete, the performance of the concrete blends tends to decline with increasing concentrations of the powder.

The findings were published in the Pertanika Journal of Science and Technology.

"Overall, there is potential for using DWSP as a partial cement replacement," the researchers said.

"However, more detailed research should be conducted to yield better quality powder," they added.​

​London, June 27 (IANS) Space-based detector can spot at least two gravitational waves -- ripples in space-time -- each year caused by collisions between supermassive black holes, revealing the initial mass of the seeds from which the first black holes grew 13 billion years ago.

A space-based instrument called the Evolved Laser Interferometer Space Antenna (eLISA) detector is set to be launched in 2034.

As eLISA will be in space - and will be at least 250,000 times larger than detectors on Earth - it should be able to detect the much lower frequency gravitational waves caused by collisions between supermassive black holes that are up to a million times the mass of our sun.

Scientists led by Durham University's Institute for Computational Cosmology ran the huge cosmological simulations that can be used to predict the rate at which gravitational waves caused by collisions between the monster black holes might be detected.

The study combined simulations from the EAGLE project - which aims to create a realistic simulation of the known Universe inside a computer - with a model to calculate gravitational wave signals.

“Understanding more about gravitational waves means that we can study the universe in an entirely different way. These waves are caused by massive collisions between objects with a mass far greater than our Sun," said lead author Jaime Salcido, PhD student in Durham University.

"By combining the detection of gravitational waves with simulations we could ultimately work out when and how the first seeds of supermassive black holes formed,” Salcido added.

In February, the international LIGO and Virgo collaborations announced that they had detected gravitational waves for the first time using ground-based instruments and in June reported a second detection.

Current theories suggest that the seeds of these black holes were the result of either the growth and collapse of the first generation of stars in the Universe; collisions between stars in dense stellar clusters; or the direct collapse of extremely massive stars in the early Universe.

As each of these theories predicts different initial masses for the seeds of supermassive black hole seeds, the collisions would produce different gravitational wave signals.

This means that the potential detections by eLISA could help pinpoint the mechanism that helped create supermassive black holes and when in the history of the Universe they formed.

“Black holes are fundamental to galaxy formation and are thought to sit at the centre of most galaxies, including our very own Milky Way,” noted co-author professor Richard Bower.

“Our research has shown how space-based detectors will provide new insights into the nature of supermassive black holes,” he added.

Gravitational waves were first predicted 100 years ago by Albert Einstein as part of his Theory of General Relativity.

The research was set to be presented at the Royal Astronomical Society's national astronomy meeting in Nottingham on Monday.​

Mumbai, June 25 (IANS) Attempting an image makeover, the Tourism Authority of Thailand (TAT) has appointed Indo-Australian actress-singer and former MTV VJ Anusha Dandekar as brand ambassador to lure more women tourists and focus on 'girly getaways' there, an official said here on Saturday.

Dandekar has been selected for her love for Thailand and for symbolising the exact segment the country wants to target, said TAT Mumbai Director Soraya Homchuen.

"Women travelers already represent 30 per cent of arrivals from India, compared to a negligible proportion of our market mix and mostly visiting families on holidays earlier. We want to scale this up to more than double by 2022," Homchuen said.

TAT will showcase Thailand as a choice for women travelers to escape together for short breaks, weekends, bachelorettes, kitty parties and girly holidays, she added.

Excited by the new assignment, Dandekar said Thailand remains her favourite destination and though she has visited it over 50 times, it never gets old for her.

Homchuen said a Thomas Cook survey this year revealed 70 per cent of women prefer to travel with friends compared to family and love the local culture, cuisine, shopping, spa and wellness, and move without a tour manager.

"The women travelers prefer safe, easy-to-navigate destinations and Thailand fits all these requirements the best," she pointed out.

Referring to various global studies showing that nearly 80 per cent of all holiday decisions are taken by women and between 2011-2020, the women travelers' segment would grow exponentially, she said targeting women "makes sense".

Easily accessible by a four-hour flight (Mumbai-Bangkok), tourism accounts for overall 20 per cent of Thailand's GDP with 29 million tourists from all over the world visiting the country in 2015, with a target of 100 million by 2032.​

Chicago, June 25 (IANS) Gold futures on the COMEX division of the New York Mercantile Exchange advanced sharply on Friday as Britain voted to exit the 28-nation European Union (EU).

Washington, June 24 (IANS) Researchers have developed a new technology that aims to make the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) even more sensitive to gravitational waves -- faint ripples in space-time.

The team from Massachusetts Institute of Technology (MIT) and Australian National University report on improvements to what is called a squeezed vacuum source. 

Although not part of the original Advanced LIGO design, injecting the new squeezed vacuum source into the LIGO detector could help double its sensitivity. 

This will allow detection of gravitational waves that are far weaker or that originate from farther away than is possible now.

“There are many processes in the universe that are inherently dark; they don't give off light of any colour,” said Nergis Mavalvala from MIT Kavli Institute for Astrophysics and Space Research. 

"Since many of those processes involve gravity, we want to observe the universe using gravity as a messenger,” Mavalvala said in a paper that appeared in the Optica. 

Scientists at Advanced LIGO announced the first-ever observation of gravitational waves earlier this year -- a century after Albert Einstein predicted their existence in his general theory of relativity. 

Studying gravitational waves can reveal important information about cataclysmic astrophysical events involving black holes and neutron stars.

Researchers from the California Institute of Technology and MIT conceived, built, and operate identical Advanced LIGO detectors in Livingston, Louisiana and Hanford, Washington. 

Each observatory uses a 2.5-mile-long optical device known as an interferometer to detect gravitational waves coming from distant events, such as the collision of two black holes detected last year.

The researchers are planning to add their new squeezed vacuum source to Advanced LIGO in the next year or so. 

Once implemented, it will improve the sensitivity of the gravitational detectors, particularly at the higher frequencies important for understanding the composition of neutron stars. 

These extremely dense stars contain the mass of the sun, which has a radius of 700,000 km, within just a 10-km diameter.​

New York, June 24 (IANS) A team of researchers has developed the first scalable method to identify different subtypes of neurons in the human brain.

The research lays the groundwork for "mapping" the gene activity in the human brain and could help provide a better understanding of brain functions and disorders, including Alzheimer's, Parkinson's, schizophrenia and depression.

By isolating and analysing individual human brain cells, researchers identified 16 neuronal subtypes in the cerebral cortex -- the brain's outer layer of neural tissue responsible for cognitive functions including memory, attention and decision making. 

"We are providing a unified framework to look at and compare individual neurons, which can help us find out how many unique types of neurons exist," said Kun Zhang, bioengineering professor at University of California-San Diego.

Researchers can use these different neuronal subtypes to build what Zhang calls a "reference map" of the human brain -- a foundation to understand the differences between a healthy brain and a diseased brain.

"In the future, patients with brain disorders or abnormalities could be diagnosed and treated based on how they differ from the reference map. This is analogous to what's being done with the reference human genome map," Zhang noted.

The team, led by University of California-San Diego, The Scripps Research Institute (TSRI) and US-based life science research company Illumina, published their findings in the journal Science.​

​New York, June 25 (IANS) The US space agency is planning to drive the Curiosity Rover towards water sites on the Martian surface to further investigate the long, seasonally changing dark streaks briny water in the hope of finding evidence of life.

"It is not as simple as driving a rover to a potential site and taking a scoop of soil," said Jim Green, NASA's director of planetary science.

"Not only are these on steep slopes, we need to ensure that planetary protection concerns are met. In other words, how can we search for evidence of life without contaminating the sites with bugs from Earth?," he added in a NASA statement.

After approval of mission extension, NASA's Curiosity Mars rover would continue to climb to higher and younger strata on Mount Sharp -- mountain in Gale crater -- to investigate how the ancient, water-rich environments found till now persisted as the red planet dried out. 

A stroll on these destinations would help the one-tonne rover closer to locations where dark streaks are present on slopes and allow it to capture images of the potential water sites from miles away and see if any are the seasonally changing type.

NASA's High-Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter (MRO) has observed many features of interest. They appear as dark lines that appear to ebb and flow over time. 

"Planetary scientists think these gullies or recurring slope lineae (RSLs) may appear seasonally as a form of briny water at or near the surface of the Red Planet under warmer conditions," NASA said.

NASA is also worried about how close could the rover safely get to an RSL? 

"In terms of coming much closer, we need to understand well in advance the potential for Earth organisms to come off the rover and that will tell us how far away the rover should stay," said Catharine Conley, NASA's planetary protection officer.

The darkish streaks are considered "special regions" on Mars, where extra precautions must be taken to prevent contamination because of the suspected presence of liquid water, considered a prerequisite for life.​