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Comment by Dr. Krishna Kumari Challa on April 23, 2017 at 11:49am

Scientists Created a Fluid With 'Negative Mass'

Researchers in the US say they've created a fluid with negative mass in the lab... 

What it means is that, unlike pretty much every other known physical object, when you push this fluid, it accelerates backwards instead of moving forwards. Such an oddity could tell scientists about some of the strange behaviour that happens within black holes and neutron stars.

 

Negative mass?! What is it?

Hypothetically speaking, matter should be able to have negative mass in the same way that an electric charge can be either negative or positive.

On paper that works, but it's still debated in the science world whether negative mass objects can really exist without breaking the laws of Physics. Isaac Newton's 2nd law of motion is often written as the formula f=ma, or force equals an object's mass times its acceleration.

If we rewrite it as acceleration is equal to a force divided by the object's mass, and make the mass negative, it would have negative acceleration - just imagine sliding a glass across a table and having it push back against your hand.

This is possible, and previous theoretical research has shown some evidence that negative mass could exist within our Universe without breaking the theory of general relativity.

many physicists think that negative mass could be linked to some of the weird things we've detected in the Universe, such as dark energy, black holes and neutron stars

Now researchers from WS univ. they've successfully managed to get a fluid of superchilled atoms to act as though it has negative mass - and suggest it could finally be used to study some of the stranger phenomena happening in the deep Universe.

To create this strange fluid, the team used lasers to cool rubidium atoms to a fraction above absolute zero, creating what's known as a Bose-Einstein condensate. 

In this state, particles move incredibly slowly and follow the strange principles of quantum mechanics, rather than classical physics - which means they start to behave like waves, with a location that can't be precisely pinpointed.

The particles also sync up and move in unison, forming what's known as a superfluid - a substance that flows without losing energy to friction.

The team used lasers to keep this superfluid at the icy temperatures, but also to trap it in a tiny bowl-like field measuring less than 100 microns across.

While the superfluid remained contained in that space it had regular mass and, as far as Bose-Einstein condensates go, was pretty normal. But then the team forced the superfluid to escape.

Using a second set of lasers, they kicked the atoms back and forth to change their spin, breaking the 'bowl' and allowing the rubidium to come rushing out so fast that it behaved as if it had negative mass.

Once you push, it accelerates backwards. It looks like the rubidium hits an invisible wall.

It's yet to be seen whether this escaping superfluid will be reliable and accurate enough to test out some of the very strange suggestions about negative mass in the lab, and before we get too excited, other teams need to replicate the results independently.

But the research has now been published in the  Physical Review Letters 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.155301

 

Comment by Dr. Krishna Kumari Challa on April 20, 2017 at 8:47am

Stand up and march for science

On April 22, protesters will converge in cities around the world to march for scientific freedom and integrity. 

Do join us and support science.

Comment by Dr. Krishna Kumari Challa on April 18, 2017 at 6:38am

Scientists have created a device that can literally extract water from the air using solar power which could one day provide “personalized water” to those in areas affected by chronic drought.

Researchers at Massachusetts Institute of Technology (MIT) and the University of California Berkeley published their findings in the journal Science on 13th April, 2017.

The invention can harvest water from the atmosphere in conditions where relative humidity is as low as 20 percent, which makes it potentially usable in many of the planet's driest regions.

Atmospheric water is a resource equivalent to ~10% of all fresh water in lakes on Earth. However, an efficient process for capturing and delivering water from air, especially at low humidity levels (down to 20%), has not been developed. Now the scientists report the design and demonstration of a device based on porous metal-organic framework-801 [Zr6O4(OH)4(fumarate)6] that captures water from the atmosphere at ambient conditions using low-grade heat from natural sunlight below one sun (1 kW per square meter). This device is capable of harvesting 2.8 liters of water per kilogram of MOF daily at relative humidity levels as low as 20%, and requires no additional input of energy.

http://science.sciencemag.org/content/early/2017/04/12/science.aam8743

Comment by Dr. Krishna Kumari Challa on April 11, 2017 at 7:57am

Personalised cancer treatment ...

• Drugs need to be specific for each patient’s genetic and immunological profile

• Side-effects of medication can be predicted by first testing them on stem cells

• The studies could lead to mapping of ethno-specific adverse effects of cancer drugs

http://www.nature.com/articles/srep41238

http://www.nature.com/articles/ncomms14565

http://www.scidev.net/global/genomics/news/personalised-cancer-gene...

Comment by Dr. Krishna Kumari Challa on April 11, 2017 at 6:58am

Comment by Dr. Krishna Kumari Challa on April 8, 2017 at 6:45am

Turbulence strong enough to injure airline passengers and crew could become twice as common because of climate change, a study has found.

Thousands of people are hurt during flights each year as turbulence causes aircraft to rise or fall rapidly without warning. Most cases are minor but there are hundreds of serious injuries and dozens of deaths, mainly on small planes.

Rising carbon dioxide emissions are increasing the temperature difference between bands of air at cruising altitude, according to research by the University of Reading. This strengthens the jet stream, the ribbon of strong winds which flows from west to east around the planet.

The acceleration of the jet stream is causing it to become less stable. Layers of air within it move at different speeds and this difference is increasing as the planet warms, producing more turbulence for aircraft.

The researchers found that the growth in the amount of CO2 in the atmosphere expected by 2050 could increase severe turbulence by at least 85 per cent.

During such severe turbulence, an aircraft’s altitude can deviate suddenly by around 100ft up or down, causing anyone unbuckled and any unsecured object to be thrown around the cabin.

The study, published in the journal Advances in Atmospheric Sciences, said that increased turbulence might not result in a rise in injuries if airlines became better at forecasting it and taking avoiding action.

Comment by Dr. Krishna Kumari Challa on April 7, 2017 at 7:13am

Chemical weapons - how they work - video

Comment by Dr. Krishna Kumari Challa on April 6, 2017 at 6:36am

A Graphene-Based Sieve That Turns Seawater Into Drinking Water

We need drinking water but with the ever shrinking drinkable water sources, we have to make do with saline water available abundantly in seas and oceans across the world. Scientists now have found a way to convert sea water to pure water.
The invention of a graphene-oxide membrane that sieves salt right out of seawater is unique.

At this stage, the technique is still limited to the lab, but it's a demonstration of how we could one day quickly and easily turn one of our most abundant resources, seawater, into one of our most scarce - clean drinking water.

The team, led by Rahul Nair from the University of Manchester in the UK, has shown that the sieve can efficiently filter out salts, and now the next step is to test this against existing desalination membranes.
Graphene-oxide membranes have long been considered a promising candidate for filtration and desalination, but although many teams have developed membranes that could sieve large particles out of water, getting rid of salt requires even smaller sieves that scientists have struggled to create.

One big issue is that, when graphene-oxide membranes are immersed in water, they swell up, allowing salt particles to flow through the engorged pores.

The Manchester team overcame this by building walls of epoxy resin on either side of the graphene oxide membrane, stopping it from swelling up in water.
This allowed them to precisely control the pore size in the membrane, creating holes tiny enough to filter out all common salts from seawater.

The key to this is the fact that when common salts are dissolved in water, they form a 'shell' of water molecules around themselves.

"Water molecules can go through individually, but sodium chloride cannot. It always needs the help of the water molecules," Nair said.

"The size of the shell of water around the salt is larger than the channel size, so it cannot go through."

Not only did this leave seawater fresh to drink, it also made the water molecules flow way faster through the membrane barrier, which is perfect for use in desalination.

"When the capillary size is around one nanometre, which is very close to the size of the water molecule, those molecules form a nice interconnected arrangement like a train," Nair explained .

"That makes the movement of water faster: if you push harder on one side, the molecules all move on the other side because of the hydrogen bonds between them. You can only get that situation if the channel size is very small."

Graphene oxide is also a lot easier and cheaper to make in the lab than single-layers of graphene, which means the technology will be affordable and easy to produce.
http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2017.2...

Comment by Dr. Krishna Kumari Challa on March 31, 2017 at 6:58am

Particles that cover the surface of Saturn's largest moon, Titan, are "electrically charged" and can cling together for months, scientists have found for the first time.

When the wind blows hard enough, Titan's non-silicate granules get kicked up and start to hop in a motion referred to as saltation. As they collide, they become frictionally charged, like a balloon rubbing against your hair, and clump together in a way not observed for sand dune grains on Earth - they become resistant to further motion. They maintain that charge for days or months at a time and attach to other hydrocarbon substances, much like packing peanuts used in shipping boxes here on Earth.

"If you grabbed piles of grains and built a sand castle on Titan, it would perhaps stay together for weeks due to their electrostatic properties," said Josef Dufek, from Georgia Institute of Technology in the US.

"Any spacecraft that lands in regions of granular material on Titan is going to have a tough time staying clean. Think of putting a cat in a box of packing peanuts," Dufek. The electrification findings may help explain an odd phenomenon. Prevailing winds on Titan blow from east to west across the moon's surface, but sandy dunes nearly 300 feet tall seem to form in the opposite direction.

"These electrostatic forces increase frictional thresholds," said Josh Mendez Harper, a doctoral student at Georgia Tech. "This makes the grains so sticky and cohesive that only heavy winds can move them. The prevailing winds aren't strong enough to shape the dunes," said Mendez Harper.

The findings have just been published in the journal Nature Geoscience.

Comment by Dr. Krishna Kumari Challa on March 15, 2017 at 8:20am

Good news for people who dye their hair...Safer Hair Dye

You no more need to worry about allergic reactions while dying your hair. Because Researchers from Gyeongsang National University have mimicked melanin to produce a dye that is less allergenic than the existing chemical used to dye hair black. Their report appears in the journal ACS Biomaterials Science & Engineering. 

Scientists have recently developed a potentially safer alternative by mimicking the hair's natural color molecule: melanin. The permanent hair dye ingredient p-phenylenediamine (PPD) has been associated, although rarely, with allergic reactions including facial swelling and rashes. Coloring hair with natural melanin would be an intuitive alternative to PPD. 

Polydopamine with iron ions transformed gray hairs into black and lasted through three wash cycles. Lighter shades could also be achieved with polydopamine by pairing it with copper and aluminum ions. Toxicity tests showed that mice treated with the colorant didn't have noticeable side effects, while those that received a PPD-based dye developed bald spots. 

http://pubs.acs.org/doi/abs/10.1021/acsbiomaterials.7b00031

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