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Archive for the ‘chemistry’ category: Page 239

Jul 7, 2021

Ancient Diamonds Show Earth Was Primed for Life’s Explosion of Diversity at Least 2.7 Billion Years Ago

Posted by in categories: alien life, chemistry

A unique study of ancient diamonds has shown that the basic chemical composition of the Earth’s atmosphere which makes it suitable for life’s explosion of diversity was laid down at least 2.7 billion years ago. Volatile gases conserved in diamonds found in ancient rocks were present in similar proportions to those found in today’s mantle, which in turn indicates that there has been no fundamental change in the proportions of volatiles in the atmosphere over the last few billion years. This shows that one of the basic conditions necessary to support life, the presence of life-giving elements in sufficient quantity, appeared soon after Earth formed, and has remained fairly constant ever since.

Presenting the work at the Goldschmidt Geochemistry Conference, lead researcher Dr. Michael Broadly said, “The proportion and make-up of volatiles in the atmosphere reflects that found in the mantle, and we have no evidence of a significant change since these diamonds were formed 2.7 billion years ago.”

Volatiles, such as hydrogen, nitrogen, neon, and carbon-bearing species are light chemical elements and compounds, which can be readily vaporized due to heat, or pressure changes. They are necessary for life, especially carbon and nitrogen. Not all planets are rich in volatiles; Earth is volatile-rich, as is Venus, but Mars and the Moon lost most of their volatiles into space. Generally, a planet rich in volatiles has a better chance of sustaining life, which is why much of the search for life on planets surrounding distant stars (exoplanets) has focused on looking for volatiles.

Jul 6, 2021

Methane in the Plumes of Saturn’s Moon Enceladus: Possible Signs of Life?

Posted by in categories: biological, chemistry, food, space

An unknown methane-producing process is likely at work in the hidden ocean beneath the icy shell of Saturn’s moon Enceladus, suggests a new study published in Nature Astronomy by scientists at the University of Arizona and Paris Sciences & Lettres University.

Giant water plumes erupting from Enceladus have long fascinated scientists and the public alike, inspiring research and speculation about the vast ocean that is believed to be sandwiched between the moon’s rocky core and its icy shell. Flying through the plumes and sampling their chemical makeup, the Cassini spacecraft detected a relatively high concentration of certain molecules associated with hydrothermal vents on the bottom of Earth’s oceans, specifically dihydrogen, methane and carbon dioxide. The amount of methane found in the plumes was particularly unexpected.

“We wanted to know: Could Earthlike microbes that ‘eat’ the dihydrogen and produce methane explain the surprisingly large amount of methane detected by Cassini?” said Régis Ferrière, an associate professor in the University of Arizona Department of Ecology and Evolutionary Biology and one of the study’s two lead authors. “Searching for such microbes, known as methanogens, at Enceladus’ seafloor would require extremely challenging deep-dive missions that are not in sight for several decades.”

Jul 4, 2021

Solar device generates electricity and desalinates water with no waste brine

Posted by in categories: chemistry, climatology, solar power, sustainability

Physics World


A device that can generate electricity while desalinating seawater has been developed by researchers in Saudi Arabia and China, who claim that their new system is highly efficient at performing both tasks. The device uses waste heat from the solar cell for desalination, thereby cooling the solar cell. It also produces no concentrated brine as waste, cutting its potential environmental impact.

In many parts of the world, climate change and population growth are putting huge demands on freshwater supplies. In some coastal regions, desalination – removing the salt from brackish water or seawater to turn it into fresh water – is increasingly being used to meet demand. Indeed, there are now around 16000 desalination plants around the world producing about 95 million cubic metres of freshwater every day.

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Jul 2, 2021

Molecular machines talk to living cells for the first time

Posted by in categories: biotech/medical, chemistry, nanotechnology

For the first time, an artificial molecular motor has been created that can ‘talk’ to living cells – by gently pulling their surface with enough physical force to elicit a biochemical response. The approach could help scientists decode the language that cells use to communicate with each other in tissues.

‘There is a mechanical language in the form of physical forces applied by the cells themselves, and we want to understand what information is communicated and what the consequences are,’ explains Aránzazu del Campo, who led the study at the Leibniz Institute for New Materials, Germany. ‘Ultimately, we want to be able to provide signals to cells and guide their function when they are not able to do that by themselves in disease cases.’

Usually, studying how cells communicate by sensing mechanical stimuli and producing biochemical responses requires prodding them with pipettes or the tip of an atomic force microscope. However, this doesn’t work at the more complex tissue level.

Jul 1, 2021

How Pesticide Companies Corrupted the EPA and Poisoned America

Posted by in categories: biotech/medical, chemistry, food, health, law

“I realized that in the middle-dose group, which is the one that mattered for the no-effects level, they had conveniently left out one of the two baseline measurement days,” said Sheppard. “The outrageous thing was that the group they declared as NOEL was only that because they left out data from their analysis.” In a peer-reviewed paper published in October 2020, Sheppard and her colleagues concluded that “the omission of valid data without justification was a form of data falsification.”


In any case, bifenthrin was not the only pesticide that dodged testing to see if it presented dangers. The EPA’s pesticide office granted 972 industry requests to waive toxicity tests between December 2011 and May 2018, 89 percent of all requests made. Among the tests on pesticides that were never performed were 90 percent of tests looking for developmental neurotoxicity, 92 percent of chronic cancer studies, and 97 percent of studies looking at how pesticides harm the immune system.

By law, the companies that submit their products for review pay for these tests, and in a presentation about the waivers last year, Anna Lowit, a senior science adviser in the office, emphasized the savings to these companies: more than $300 million. Lowit also noted that animal lives were saved — a goal that the Trump administration and the chemical industry prioritized within the agency. The EPA developed the guidelines for waiving the tests along with BASF, Corteva, and Syngenta, pesticide manufacturers that all stand to benefit significantly from having their products bypass toxicity testing.

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Jul 1, 2021

New five-metal alloy makes for 2D catalyst to convert CO2 into fuels

Posted by in categories: chemistry, particle physics, sustainability

Researchers have created an unusual new alloy made up of not two, but five different metals, and put it to work as a catalyst. The new material is two-dimensional, and was able to convert carbon dioxide into carbon monoxide effectively, potentially helping to turn the greenhouse gas into fuels.

The new alloy belongs to a class of materials called transition metal dichalcogenides (TMDCs), which are, as the name suggests, made up of combinations of transition metals and chalcogens. Extremely thin films of TMDCs have recently shown promise in a range of electronic and optical devices, but researchers on the new study wondered if they could also be used as catalysts for chemical reactions.

The thinking goes that because reactions occur on the surface of a catalyst, materials with high surface areas will be more effective catalysts. And as sheets only a few atoms thick, TMDCs are almost nothing but surface area.

Jun 30, 2021

Garage Semiconductor Fab Gets Reactive-Ion Etching Upgrade

Posted by in categories: chemistry, computing

It’s a problem that few of us will likely ever face: once you’ve built your first homemade integrated circuit, what do you do next? If you’re [Sam Zeloof], the answer is clear: build better integrated circuits.

At least that’s [Sam]’s plan, which his new reactive-ion etching setup aims to make possible. While his Z1 dual differential amplifier chip was a huge success, the photolithography process he used to create the chip had its limitations. The chemical etching process he used is a bit fussy, and prone to undercutting of the mask if the etchant seeps underneath it. As its name implies, RIE uses a plasma of highly reactive ions to do the etching instead, resulting in finer details and opening the door to using more advanced materials.

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Jun 29, 2021

Speedy nanorobots could someday clean up soil and water, deliver drugs

Posted by in categories: biotech/medical, chemistry, engineering

University of Colorado Boulder researchers have discovered that minuscule, self-propelled particles called “nanoswimmers” can escape from mazes as much as 20 times faster than other passive particles, paving the way for their use in everything from industrial clean-ups to medication delivery.

The findings, published this week in the Proceedings of the National Academy of Sciences, describe how these tiny synthetic nanorobots are incredibly effective at escaping cavities within maze-like environments. These nanoswimmers could one day be used to remediate contaminated soil, improve water filtration or even deliver drugs to targeted areas of the body, like within dense tissues.

“This is the discovery of an entirely new phenomenon that points to a broad potential range of applications,” said Daniel Schwartz, senior author of the paper and Glenn L. Murphy Endowed Professor of chemical and biological engineering.

Jun 29, 2021

Railroads To Pour Cold Renewable Energy Water On Koch Industries

Posted by in categories: business, chemistry, energy, sustainability, transportation

The US power grid needs all of support it can get. Sad that some would stand in the way of progress.


There is no love lost between the notorious Koch brothers and the nation’s railroad industry, and the relationship is about to get a lot unlovelier. A massive new, first-of-its-kind renewable energy transmission line is taking shape in the Midwest, which will cut into the Koch family’s fossil energy business. It has a good chance of succeeding where others have stalled, because it will bury the cables under existing rights-of-way using railroad rights-of-way and avoid stirring up the kind of opposition faced by conventional above-ground lines.

The Koch brothers and their family-owned company, Koch Industries, have earned a reputation for attempting to throttle the nation’s renewable energy sector. That makes sense, considering that the diversified, multinational firm owns thousands of miles of oil, gas, and chemical pipelines criss-crossing the US (and sometimes breaking down) in addition to other major operations that depend on rail and highway infrastructure.

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Jun 28, 2021

Scientists obtain magnetic nanopowder for 6G technology

Posted by in categories: chemistry, internet

Material scientists have developed a fast method for producing epsilon iron oxide and demonstrated its promise for next-generation communications devices. Its outstanding magnetic properties make it one of the most coveted materials, such as for the upcoming 6G generation of communication devices and for durable magnetic recording. The work was published in the Journal of Materials Chemistry C, a journal of the Royal Society of Chemistry.

Iron (III) is one of the most widespread oxides on Earth. It is mostly found as the mineral hematite (or alpha , α-Fe2O3). Another stable and common modification is maghemite (or gamma modification, γ-Fe2O3). The former is widely used in industry as a red pigment, and the latter as a magnetic recording medium. The two modifications differ not only in crystalline structure (alpha-iron oxide has hexagonal syngony and gamma-iron oxide has cubic syngony) but also in magnetic properties.

In addition to these forms of iron oxide (III), there are more exotic modifications such as epsilon-, beta-, zeta-, and even glassy. The most attractive phase is epsilon iron oxide, ε-Fe2O3. This modification has an extremely high coercive force (the ability of the material to resist an external magnetic field). The strength reaches 20 kOe at room temperature, which is comparable to the parameters of magnets based on expensive rare-earth elements. Furthermore, the material absorbs in the sub-terahertz frequency range (100−300 GHz) through the effect of natural ferromagnetic resonance. The frequency of such resonance is one of the criteria for the use of materials in wireless communications devices—the 4G standard uses megahertz and 5G uses tens of gigahertz. There are plans to use the sub-terahertz range as a working range in the sixth generation (6G) , which is being prepared for active introduction in our lives from the early 2030s.