Why is Plastic Non-biodegradable?

Most plastic is manufactured from petroleum the end product of a few million years of natural decay of once-living organisms. Petroleum’s main components come from lipids that were first assembled long ago in those organisms’ cells. So the question is, if petroleum-derived plastic comes from biomaterial, why doesn’t it biodegrade?

A crucial manufacturing step turns petroleum into a material unrecognized by the organisms that normally break organic matter down.

Most plastics are derived from propylene, a simple chemical component of petroleum. When heated up in the presence of a catalyst, individual chemical units monomers of propylene link together by forming extremely strong carbon-carbon bonds with each other. This results in polymers long chains of monomers called polypropylene.

“Nature doesn’t make things like that,” said Kenneth Peters, an organic geochemist at Stanford University, “so organisms have never seen that before.”

The organisms that decompose organic matter the ones that start turning your apple brown the instant you cut it open “have evolved over billions of years to attack certain types of bonds that are common in nature,” Peters told Life’s Little Mysteries.

“For example, they can very quickly break down polysaccharides to get sugar. They can chew up wood. But they see a polypropylene with all its carbon-carbon bonds, and they don’t normally break something like that down so there aren’t metabolic pathways to do it,” he said.

But if all you have to do to make propylene subunits turn into polypropylene is heat them up, why doesn’t nature ever build polypropylene molecules?

According to Peters, it’s because the carbon-carbon bonds in polypropylene require too much energy to make, so nature chooses other alternatives for holding together large molecules. “It’s easier for organisms to synthesize peptide bonds than carbon-carbon bonds,” he said. Peptide bonds, which link carbon to nitrogen, are found in proteins and many other organic molecules.

Environmentalists might wonder why plastic manufacturers don’t use peptide bonds to build polymers rather than carbon-carbon bonds, so that they’ll biodegrade rather than lasting forever in a landfill . Unfortunately, while peptide bonds would produce plastics that biodegrade, they would also have a very short shelf life. “It’s an issue of ‘you can’t have your cake and eat it too,'” said Jim Coleman, chief scientist at the US Geological Survey Energy Resources Program. “When you buy a plastic jar of mayonnaise, you want [the jar] to last a few months.” You don’t want it to start decomposing before you’ve finished the mayo inside.

For the original article visit livescience.com!

[Photo Credit: Antonio Oquias | Dreamstime]

Mental Health and Climate

Here is an excerpt from the 2017 APA Mental Health on Climate white-paper:

The ability to process information and make decisions
without being disabled by extreme emotional responses is
threatened by climate change. Some emotional response is
normal, and even negative emotions are a necessary part of
a fulfilling life. In the extreme case, however, they can interfere
with our ability to think rationally, plan our behavior, and
consider alternative actions. An extreme weather event can
be a source of trauma, and the experience can cause
disabling emotions. More subtle and indirect effects of
climate change can add stress to people’s lives in varying
degrees. Whether experienced indirectly or directly, stressors
to our climate translate into impaired mental health that can
result in depression and anxiety (USGCRP, 2016). Although
everyone is able to cope with a certain amount of stress,
the accumulated effects of compound stress can tip a
person from mentally healthy to mentally ill. Even uncertainty
can be a source of stress and a risk factor for psychological
distress (Greco & Roger, 2003). People can be negatively
affected by hearing about the negative experiences of
others, and by fears—founded or unfounded—about their
own potential vulnerability.
Compromised physical health can be a source of stress
that threatens psychological well-being. Conversely, mental
health problems can also threaten physical health, for
example, by changing patterns of sleep, eating, or exercise
and by reducing immune system function.
Although residents’ mental and physical health affect
communities, the impacts of climate on community health
can have a particularly strong effect on community fabric
and interpersonal relationships. Altered environmental
conditions due to climate change can shift the opportunities
people have for social interaction, the ways in which they
relate to each other, and their connections to the
natural world.

Link to article: https://www.apa.org/news/press/releases/2017/03/mental-health-climate.pdf

Hot Solar Cell

As posted in the MIT Technology Review earlier this year, we are developing a new “hot solar cell” technology.
By converting heat to focused beams of light, a new solar device could create cheap and continuous power.

Solar panels cover a growing number of rooftops, but even decades after they were first developed, the slabs of silicon remain bulky, expensive, and inefficient. Fundamental limitations prevent these conventional photovoltaics from absorbing more than a fraction of the energy in sunlight.

But a team of MIT scientists has built a different sort of solar energy device that uses inventive engineering and advances in materials science to capture far more of the sun’s energy. The trick is to first turn sunlight into heat and then convert it back into light, but now focused within the spectrum that solar cells can use. While various researchers have been working for years on so-called solar thermophotovoltaics, the MIT device is the first one to absorb more energy than its photovoltaic cell alone, demonstrating that the approach could dramatically increase efficiency.

Visit the full source article here!

REON II Water Quality Sensor Device

In the race to find solutions to critical water issues, the launch of a new cost-effective water quality sensor device by Beacon Institute for Rivers and Estuaries|Clarkson University is the first step in overcoming hurdles of historically prohibitive costs for long-term water resource monitoring.

The installation of the Institute’s newest generation of River and Estuary Observatory Network (REON II) sensor arrays signifies the passing of the baton from the science lab to the river as they run ahead, complementing government capacity to invest in “wiring” the river for cleaner water.

The REON II device or “Sonde,” deployed on the banks of the Hudson River in New Hamburg, N.Y., is providing real-time data called for by scientists to better understand the complex relationship between humans, the built environment and our fragile waterways.

It is one of 37 sensor stations currently in place in the Hudson and St. Lawrence river watersheds, making REON one of the world’s most robust resources of real-time data. The goal of the REON research team to develop affordable, scalable, low-profile sensor networks and its potential for making water sensor technology universal, could be transformational to the field of environmental science.

CEF FFT: The more up-to-date and accurate the data we can collect on the water quality of rivers and estuaries, the more we can become aware of the impact our civilization has on these precious sources of life.

To read more and watch a video, visit the source link here.