Suramya's Blog : Welcome to my crazy life…

August 14, 2019

Sun Plasma & Solar wind recreated in a Lab

Filed under: Interesting Sites,News/Articles — Suramya @ 6:55 PM

It’s safe to say that without the Sun life would not exist on Earth and this fact was known even during ancient times when the Sun was worshiped as a God. Over the years scientific advances allowed us to learn more about the Sun and we figured out that it was a Star and like all stars made up mostly of Hydrogen and other gases. However the temperature there is so hot that most of the gas actually exists as plasma, the fourth state of matter. (This is not the same Plasma as what’s in our blood) To recap, the first state of matter is a Solid, when that is heated it will convert to Liquid state and then to gaseous state. When gas is superheated atoms break apart into charged particles turning it into plasma.

Even though we can see the sun there are a lot of mysteries about how things work in it. For example, we know that Sun has a magnetic field that we think is generated because of the spinning Plasma and this along with the temperature of the plasma creates charged particles that can escape from the Sun’s gravity, which is called Solar Wind and is of great interest because so far, we didn’t know exactly how/why these plasmas escape the sun’s magnetic fields. There are efforts ongoing to directly study the phenomenon directly, for example we have the Parker Solar Probe which was launched in August 2018 which is expected to reach and even dip below the Alfvén surface (The point some distance from the sun’s surface, where the magnetic field weakens and plasma breaks away from the sun) but that is expensive and not always available. Plus we can only observer a limited area at a time due to the sheer size of Space.

So scientists set about trying to recreate the plasma layer & magnetic field in a lab and a research team from University of Wisconsin, Madison has achieved this goal by creating a 3-meter-wide plasma containment chamber called the “Big Red Ball”. In it they placed a permanent magnet about 10 centimeters wide and 10 centimeters long and filled the ball with a plasma made from helium gas and drove an electrical current through it. This created a force on the plasma that made it spin around the dipole. Using this technique, the team was able to successfully re-create the shape of the Parker spiral, as they describe in a paper published today in Nature Physics. With their mini-sun in place, the researchers can take measurements at many points inside the ball, allowing them to study solar phenomena in three dimensions. While this is not a perfect recreation of the sun, it is a significant advancement and will give us a greater understanding of how/why the sun works the way it does.

The experiment was also able to mimic a region around the sun where the plasma hangs in a precarious balance. Within this boundary, plasma’s are contained by magnetic fields, but outside it, centrifugal forces from the sun’s rotation overpower the magnetic fields, and plasmas stream outward. The researchers found that “if you spin [the plasma] hard enough, you can get it to spin out from centrifugal force,” Peterson said. The team believes that the plasma blobs they generated are analogous to those in space that fuel the sun’s slow solar wind.

Some aspects of the model, like the density of the plasma and its proportion of charged and neutral particles, don’t reflect the composition of the real sun’s corona and solar wind. But the experiment is still informative, said Aleida Higginson, a solar physicist at the Johns Hopkins University Applied Physics Laboratory who works on simulations of the solar wind and was not involved in the study. “We’re talking about lab conditions on Earth versus the sun, so there are obviously going to be some differences. I’m still impressed,” she said. “If they really did get reconnection, and got blobs, I think that’s really cool and promising.”

Overall this is very cool, and I am looking forward to more advances in this area.

Source: Sun’s Puzzling Plasma Recreated in a Laboratory

– Suramya

August 12, 2019

LinuxJournal.com: shutdown -h now

Filed under: Computer Related,My Thoughts,Techie Stuff — Suramya @ 10:24 AM

Last week I got an unpleasant surprise in my mailbox, an email from Linux Journal stating that they were closing up shop effective immediately as they had completely run out of money with no hope of resurrection. LJ was one of the first Linux magazines I wrote for and it will always have a special place in my heart.

IMPORTANT NOTICE FROM LINUX JOURNAL, LLC:
On August 7, 2019, Linux Journal shut its doors for good. All staff were laid off and the company is left with no operating funds to continue in any capacity. The website will continue to stay up for the next few weeks, hopefully longer for archival purposes if we can make it happen.
–Linux Journal, LLC

The website is up for the moment but might go down anytime. I do have an archive of all LJ issues on my home computer that I had made the last time LJ was about to shutdown and I will post them to the site in a few days. This archive doesn’t have the latest releases so I will need to download that before I post them online. In addition I am sure there are efforts ongoing to archive the website as well since it had a lot of great content on it. If not then I will kick off something to archive the site once I get home.

Well this is all for now. It was a great run LJ, you will be missed.

– Suramya

August 7, 2019

Using a slice of wood to make saltwater drinkable

Filed under: My Thoughts,Techie Stuff — Suramya @ 5:45 PM

“Water water everywhere, not a drop to drink” This is an often quoted line from The Rime of the Ancient Mariner by Samuel Taylor Coleridge and is something that is becoming more and more true every day. 71% of earth is covered by Oceans but we still have 2.8 billion people around the world who face water scarcity at least one month out of every year. Earlier this year city officials in Chennai, India declared that “Day Zero” (the day when almost no water is left in the city) had been reached in Chennai, as all the four main reservoirs supplying water to the city had run dry due to deficient monsoon rainfall in the previous years. Due to this finding more ways of generating drinking water a high priority for the Human race. Without water life as we know it can’t exist and our civilization can and will collapse.

One of the ways to solve this issue is to convert sea water to drinkable water by filtering the salt out and there are existing solutions which do this (check out the Saudi water desalination) but they require a lot of energy and/or specialized engineering. But this is about to change thanks to the effort of Jason Ren and his colleagues from Princeton University in New Jersey. They have developed a method that uses a new kind of membrane made of American basswood instead of plastic that enables filtration without requiring high pressure pumping of salt water. Basically they took a thin slice of American basswood and treated it with a chemical bath to remove extra fibers from the wood and make its surface slippery to water molecules. Once the wood is treated water flows down one side of the membrane and is heated to the point that it vaporizes. The vapor then travels through the pores in the membrane toward its colder side leaving the salt behind, condensing as fresh, cool water.

This process takes less energy than simply boiling all of the saltwater because there’s no need to maintain a high temperature for more than a thin layer of water at a time as per Jason Ren. In the initial testing using this method the team was able to filter about 20 kilograms of water per square metre of membrane per hour, which is not quite as quick as polymer membranes but this can improve if the membrane is made thinner.

This is quite a breakthrough and when I first read the article I was not clear why we need to use wood for the process. I mean we can use a polymer membrane and still achieve the same effect by heating only a thin layer of water at a time. But then I spent some time reading the actual research paper and that’s when I realized what a massive breakthrough this was. Basically the current commercial MD membranes have porosity lower than 0.80, thermal conductivity higher than 0.050 W m−1 K−1, and thermal efficiency up to 60% where as the new membrane has a porosity of ~90%, low thermal conductivity (~0.04 W m−1 K−1) and a thermal efficiency of ~71%. These factors combined reduce the energy requirements for desalination by a significant amount.

Now that we have a Proof of Concept that this works, we need to be able to scale this up on a massive scale and work for this is currently ongoing.

Thanks to Newscientist.com for the original link.
Research Paper: Hydrophobic nanostructured wood membrane for thermally efficient distillation

Well this is all for now. Will post more later.

– Suramya

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