The Light Side: Those Multiphase Turbulent Buoyant Clouds We Sneeze

April 11, 2014

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Based on new research that is realizing germophobes' worst nightmares, scientists and engineers at the Massachusetts Institute of Technology have discovered that infectious droplets from sneezes and coughs can travel, en masse, a whopping 200 times further than previously thought. If it sounds as though these droplets gain a life of their own, that's because high-speed imaging of coughs and sneezes, lab simulations, and mathematical modeling at MIT have detected that they can form and stay suspended as gas clouds and move aloft over great distances.

The MIT researchers are calling the phenomenon "multiphase turbulent buoyant cloud" and debunking the conventional wisdom that these potentially infectious droplets drift as groups of unconnected particles. And it's not the larger mucus droplets that we have to worry about; it's the smaller ones that are sinister, because they "can be swept around and resuspended by the eddies within a cloud, and so settle more slowly," according to a MIT article publicizing the findings.

John Bush, a MIT professor of applied mathematics, and one of the researchers, said, "If you ignored the presence of the gas cloud, your first guess would be that larger drops go farther than smaller ones, and travel at most a couple of meters," referring to the momentum principle of mass times velocity. "But by elucidating the dynamics of the gas cloud, we have shown that there's a circulation within the cloud."

Bush, who co-authored a study with two other researchers that was featured in the Journal of Fluid Mechanics, continued, "Basically, small drops can be carried a great distance by this gas cloud while the larger drops fall out. So you have a reversal in the dependence of range on size."

The ominous theory to come out of this study is that the ventilation systems used in confined spaces, such as offices, airplanes, and hospitals, may actually be acting as accomplices for the invisible menaces that we expel. These systems may be carrying the gas clouds more directly to people, transmitting airborne pathogens. This would rewrite the way architects and engineers design built environments to minimize infections.

MIT researchers will continue to delve deeper into the behaviors of sneezed droplets, developing additional examination tools. They hope to determine how infectious diseases spread indoors and how epidemics are created. Correlations between air conditions and the range of expelled pathogens could arise from further research.

In the meantime, it might seem truly wise now to keep a gas mask handy in the office desk drawer.

Study: Excess Tweeting Can Lead to Broken Relationships

A research study by a University of Missouri doctoral student confirms what we have seen with high-profile people like disgraced politician Anthony Weiner: overuse of Twitter can lead to emotional (if not physical) infidelity and damaging conflict in relationships.

The study by Russell Clayton, who is studying at the university's School of Journalism, surveyed 581 Twitter users and found that the more active a person is on the social media site, the likelier it was for that person to experience a negative relationship outcome. So-called Twitter-related conflict led to breakup or divorce.

"I found it interesting that active Twitter users experienced Twitter-related conflict and negative relationship outcomes regardless of length of romantic relationship," Clayton said in a university news release.

"Although a number of variables can contribute to relationship infidelity and separation, social networking site usage... can be damaging to relationships," he continued. "Therefore, users should cut back to moderate, healthy levels of Twitter use if they are experiencing Twitter or Facebook-related conflict."

Respondents' answers to Clayton's survey suggested that overactive use of the social site caused suspicion, jealousy, and arguments from significant others. Aside from spending less time on Twitter, the use of joint site accounts can reduce relationship conflict, in a social media-age iteration of couples therapy.

Clayton's study, "The Third Wheel: The Impact of Twitter Use on Relationship Infidelity and Divorce," was published in the peer-reviewed journal Cyberpsychology, Behavior, and Social Networking.

Personalized Medicine on a Wearable Patch

Imagine treating a debilitating illness simply by slapping on an electronic patch and forgetting that your condition even exists. While that future may seem fantastical and far-fetched, it could become a reality in the very near future.

nature, nanotechnology, medicine, cancer, gold, chromiumAccording to a paper published in Nature Nanotechnology, Korean researchers have developed a prototype patch that can measure muscle movement, administer medicine, and keep a log of everything it has recorded. Built using silicon nanosensors, chromium and gold nanowires, silica nanoparticles, and an adhesive pad, the new electronic monitor could be a lifesaver for patients suffering from Parkinson’s disease and other illnesses that require constant medical supervision.

As detailed by researchers, once one of the patches has been applied to the skin silicon nanosensors sense minute muscle tremors. If programmed to do so, metallic wires woven throughout the adhesive dressing heat up silicate nanoparticles that contain medication. As these particles reach temperature, medicine is released and absorbed by the skin.

While all of that micro engineering is pretty impressive, the most remarkable aspect of this sticky device might be its onboard memory that can flex, bend, and stretch to 125 percent of its original size. In fact, during the course of their study, scientists tested the patch on a number of body parts that contort in various ways, finding that their monitor will stay put no matter where it’s applied.

[This] system represents a new direction in personalized health care that will eventually enable advanced diagnostics and therapy on devices that can be worn like a child’s temporary tattoo,” said Dae-Hyeong Kim, lead researcher on the project.

In coming years, researchers are looking to improve the performance of their epidermal electronics and untether them from their power supplies. If the device could be made wireless, clinical and regulatory tests could quickly commence, and a new, more portable form of personalized medicine could be prescribed to patients suffering from disease or looking to monitor their overall well-being.

This article by Kyle Maxey was originally published on Engineering.com and is adapted in its entirety with permission. For more stories like this please visit Engineering.com. Top photo credit: MIT

 

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