Tag Archives: cornell university

New sugar polymer can purify water in seconds

Scientists have developed a new polymer that can clean water of tiny impurities and pollutants in a matter of seconds. This could revolutionize the water purification industry, not only saving numerous lives, but saving a lot of money and energy in the process.

A porous material made from cup-shaped cyclodextrins, which rapidly bind pollutants and remove them from contaminated water. © Dichtel Group

The team was led by Will Dichtel from Cornell University in the US.

“What we did is make the first high-surface-area material made of cyclodextrin [sugar molecules bound together in a ring],” said Will Dichtel, associate professor of chemistry, “combining some of the advantages of the activated carbon with the inherent advantages of the cyclodextrin.”

Cyclodextrins are produced from starch and are commonly used in foods, pharmaceutical, drug delivery, and chemical industries, as well as agriculture and environmental engineering. This porous form of cyclodextrin has adsorption rates much higher than traditional filters – up to 200 times more.

“What we did is make the first high-surface-area material made of cyclodextrin combining some of the advantages of the activated carbon with the inherent advantages of the cyclodextrin,” Mr Dichtel said. He also mentioned that the material will be extremely quick in cleaning the water. “These materials will remove pollutants in seconds, as the water flows by,” he said.

Not only is the polymer very fast and efficient, but it’s also cheap and recyclable. While most carbon filters must undergo specific heat-treatment for regeneration, this one can simply be washed at room temperature with methanol or ethanol. Even Dichtel was surprised at how efficient it can be.

“We knew that [water filtering] would be a likely application if we were successful,” Dichtel says. “We were definitely pleasantly surprised with just how good the performance is.”

Journal Reference: Alaaeddin Alsbaiee, Brian J. Smith, Leilei Xiao, Yuhan Ling, Damian E. Helbling & William R. Dichtel – Rapid removal of organic micropollutants from water by a porous β-cyclodextrin polymer. Nature (2015) doi:10.1038/nature16185

Facebook conducted psychological experiments on its users

Facebook being unethical – again

I think at this point it’s safe to say that ethics isn’t necessarily one of Facebook‘s concerns, and this study shows it once again. What am I talking about? A covert experiment which influenced the emotions of 600,000 people, without asking for permission.

The entire situation is starting to become one big Monty Python sketch. Was permission for the study granted? At first, the answer was ‘yes’, but it quickly changed to ‘no’. Then it became ‘maybe’ , but the final call was still ‘no’. Initially, they said it was funded by the US military, but then, that statement was retracted, without any single further explanation. It’s easy to understand why this caused uproar, and massive discussions about the lack of ethics regarding this study. This pretty much sums it up:

“What many of us feared is already a reality: Facebook is using us as lab rats, and not just to figure out which ads we’ll respond to but actually change our emotions,” wrote Animalnewyork.com in a blog post on Friday morning.

Cornell University and the head of the study quickly washed their hands of the whole thing, saying that they had nothing to do with the gathering of the data and the experiment, they merely interpreted the results:

“Because the research was conducted independently by Facebook and Professor Hancock had access only to results – and not to any individual, identifiable data at any time – Cornell University’s Institutional Review Board concluded that he was not directly engaged in human research.”, Cornell University said in a statement.

The social experiment

Facebook’s CEO, Mark Zuckerberg, hasn’t replied to the heavy accusations brought to Facebook.

What the experiment actually did was that for one week, they changed the content of news feeds for a random sample of Facebook users (over 600,000). For one group of users they removed content that contained positive words, for another group they removed content that contained negative words. The point was to see whether this biased way of presenting things had any effect on users’ emotions. Interestingly enough, it did – news which was presented in a more positive way had a more positive impact, and vice versa. The problem was that the users didn’t know they were participated in any research – just like with Twitter, it can be argued that the data for this study is unethical.

Scientifically, it can clearly be said that the study has a significant value. The number of people which were involved is absolutely huge – it’s quite possibly the largest sample size ever used in a psychological study – so there is a high statistical relevance. However, the statistical difference was one of the smallest ever published – so the results, while noticeable, are extremely small.

But the problems with this study isn’t that the results were small – it’s that again, Facebook didn’t get the approval of the participants. Participation in a study is at the core of science ethics since WWII, and this is simply against those ideas.

“It’s completely unacceptable for the terms of service to force everybody on Facebook to participate in experiments,” said Kate Crawford, visiting professor at MIT’s Center for Civic Media and principal researcher at Microsoft Research.

Facebook said that the study was conducted anonymously, so researchers could not learn the names of the research subjects – but the fact remained that they attempted to manipulate the feelings of some of its users without consent. They also don’t seem to care, since they didn’t even bother to clarify the situation. Gotta love Facebook!

Titan Ligeia Mare.

Never before seen “magic island” pops up on Saturn’s Moon Titan

Titan Ligeia Mare.

Titan’s Ligeia Mare. Image via NASA.

Astronomers have discovered a previously unspotted geological feature on Saturn’s moon, Titan. Pictures taken by the Cassini probe revealed a transient geological feature – a “magic island”.

Now you see it, now you don’t

The bright, mysterious object was seen in Ligeia Mare, the second-largest sea on Saturn’s moon Titan. But Cassini took pictures of that area before, and the island wasn’t spotted – which can only mean that this is a transient geological feature, something which comes and goes. It’s not exactly clear what’s the cause, but astronomers have a few ideas.

Reporting in Nature Geoscience, scientists note that this is the first time an active geological feature was observed on Titan’s surface.

“This discovery tells us that the liquids in Titan’s northern hemisphere are not simply stagnant and unchanging, but rather that changes do occur,” said Jason Hofgartner, a Cornell University graduate student in the field of planetary sciences, and the paper’s lead author. “We don’t know precisely what caused this ‘magic island’ to appear, but we’d like to study it further.”

To discover the feature, astronomers relied on an old fashioned technique – flipping. The Cassini spacecraft sent forth a lot of data, which was received in July 2013. Hofgartner and his colleagues flipped between older Titan images and newer ones, relying on their own eyes to detect any changes. Despite being quite non-technological, this technique is often used to detect asteroids, comets and other small celestial objects.

“With flipping, the human eye is pretty good at detecting change,” said Hofgartner.

With previous observations, that area of the Ligeia Mare was completely devoid of any features – including waves. But in these newer pictures, they detected something else: an island, apparently popping up out of nowhere. It’s not clear exactly why it appeared, but the theory is that it showed up as a result of season changing, which on Titan takes much longer and is much stronger than on Earth.

Titan's Ligeia Mare.

Titan’s Ligeia Mare.

There are 4 proposed mechanisms:

– The nothern winds are causing waves, and what they are seeing is in fact a “ghost island” – a continuum of waves. This is the simplest theory, and the least spectacular (very likely though).

– Gases are pushing out from the sea floor, causing bubbles to burst towards the surface.

– As the water becomes warmer, sunken objects become buoyant and float towards the surface

– Ligeia Mare has suspended solids, which are neither sunken nor floating, but act like silt in a terrestrial delta.

It’s not clear which one of these is happening (or if we are in fact dealing with something else, completely different).

“Likely, several different processes — such as wind, rain and tides — might affect the methane and ethane lakes on Titan. We want to see the similarities and differences from geological processes that occur here on Earth,” Hofgartner said. “Ultimately, it will help us to understand better our own liquid environments here on the Earth.”

Surprising Titan

Titan is one of the most interesting places in the solar system. It’s been theoretized for quite a while that the moon harbors a liquid ocean beneath its frozen surface, and recent studies seem to back that idea up. Titan also has mountains made from ice, and it sometimes gets foggy. Along with Europa and Enceladus it is one of the likeliest places in the solar system to have alien life.

Source: Cornell University.

GeoPicture of the Week: Geologic Faults

This picture from Cornell University really encapsulates the beauty of a geologic fault – it’s like someone took it from a text book and slammed into real life. In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures. You can see how the different layers (strata) of rock moved relative to each other.