Archive for the ‘chemistry’ category: Page 241
May 21, 2021
Why studying Uranus and Neptune could help us find habitable planets in other solar systems
Posted by Lawrence Klaes in categories: chemistry, space
Astronomers have long predicted that deep beneath Neptune’s thick blue clouds lies a super-hot body of water that, despite its high temperature, never boils because of its incredibly high-pressure atmosphere. Uranus, another planet in the outer solar system of similar size and composition, is also believed to have a similar water-rich interior. Unfortunately, due to their distances from Earth, it is hard to directly probe these two planets to test our assumption. But scientists have found novel ways of testing their theories about these ice giants from Earth.
As described in a newly-published study from Nature Astronomy, scientists recreated the pressure and temperature of the interiors of Neptune and Uranus in a lab. The aim of the experiments was to test hypotheses about the chemistry of the deep water within these planets. But the study could have additional implications for what we know about potentially habitable planets in other solar systems.
“We were seeking to extend our knowledge of the deep interior of ice giants and determine what water-rock interactions at extreme conditions might exist,” said lead author Taehyun Kim, of Yonsei University in South Korea. “Ice giants and some exoplanets have very deep water layers, unlike terrestrial planets. We proposed the possibility of an atomic-scale mixing of two of the planet-building materials (water and rock) in the interiors of ice giants.”
May 21, 2021
Faecal transplantation: the cure for forgetfulness?
Posted by Joe Bennett in categories: biotech/medical, chemistry, life extension, neuroscience
In our ongoing search to continuously improve our health, we occasionally pay lip service to the bacteria that live inside our gut. Normally this concern rarely manifests as anything more than occasionally remembering to buy some of those small bottles of pro-biotic yoghurts while shopping for your…
Recent discoveries have led to the conclusion that the gut plays an important role in cognitive function, with a large amount of research into understanding what is known as the gut-brain axis, which is the collective name given to the biochemical signalling pathways which take place between the gastrointestinal tract and the central nervous system. With an ever-increasing understanding of this pathway, along with an expanded understand of the gut flora (which was found to decline with age), researchers started to ask how the gut flora are involved in the ageing process.
In order to test how exactly ageing gut flora effects the gut-brain axis, researchers at the University of East Anglia conducted a faecal transplant from elderly mice into younger mice. Following this transplant, the young mice were then put through a serious of tests to assess their cognitive abilities. The younger mice showed significant changes in their microbial profiles, as well as significantly impaired capacity for spatial learning, as well as a decreased capacity for memorisation. These mice also showed an altered expression of proteins associated with neurotransmission and neuroplasticity, along with changes in the mice’s hippocampus, which is responsible for allowing the mice to memories new information, as well as recalling previous memories.
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May 21, 2021
An ancient star casts new light on the birth of the universe
Posted by Genevieve Klien in categories: chemistry, cosmology
Astronomers have discovered an exceedingly old star at the edge of our galaxy that seems to have formed only a few million years after the Big Bang – and what they are learning from it could affect their understanding of the birth of the universe.
In a study published last week, researchers found the star during an astronomical survey of the southern sky with a technique called narrowband photometry, which measures the brightness of distant stars in different wavelengths of light and can reveal stars that have low levels of heavy elements.
They then studied the star – known by its survey number as SPLUS J210428.01−004934.2, or SPLUS J2104−0049 for short – with high-resolution spectroscopy to determine its chemical makeup.
May 19, 2021
Precision test of statistical dynamics with state-to-state ultracold chemistry
Posted by Saúl Morales Rodriguéz in categories: chemistry, quantum physics
The chemical reaction 2KRb → K2 + Rb2 is studied under ultralow temperatures at the quantum state-to-state level, allowing unprecedented details of the reaction dynamics to be observed.
May 19, 2021
Deconstruction of high-density polyethylene into liquid hydrocarbon fuels and lubricants
Posted by Omuterema Akhahenda in categories: chemistry, sustainability
Plastic pollution has become one of the most pressing environmental issues now that the rapidly increased production of disposable plastic products is far beyond the world’s capacity for recycling and upcycling waste plastics. Although recent studies have provided a few catalytic strategies for producing value-added fuel and chemical products from polyethylene (PE) waste, the kinetic rates and/or selectivities are unsatisfactory, even with extended processing time (24 h) and high temperatures (280°C). This work reports a liquid-phase catalytic hydrogenolysis process that highly efficiently converts high-density PE to jet-fuel-and lubricant-range hydrocarbons under relatively mild conditions. The application of this efficient liquid-phase catalytic hydrogenolysis process could provide a promising approach for selectively producing high-value products, such as lubricants, from waste PE and other polyolefin polymers.
May 18, 2021
Study finds alarming levels of ‘forever chemicals’ in US mothers’ breast milk
Posted by Jason Blain in categories: biotech/medical, chemistry, health
They are linked to cancer, birth defects, liver disease, thyroid disease, plummeting sperm counts and a range of other serious health problems.
The peer-reviewed study, published on Thursday in the Environmental Science and Technology journal, found PFAS at levels in milk ranging from 50 parts per trillion (ppt) to more than 1850ppt.
Toxic chemicals known as PFAS found in all 50 samples tested at levels nearly 2000 times what is considered safe in drinking water.
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May 17, 2021
Recycling gives new purpose to spent nuclear fuel
Posted by Genevieve Klien in categories: chemistry, sustainability
Imagine filling up your gas tank with 10 gallons of gas, driving just far enough to burn a half gallon and discarding the rest. Then, repeat. That is essentially the practice that the U.S. nuclear industry is following.
Spent nuclear fuel from power plants still has 95% of its potential to produce electricity. Current plans are to dispose of the spent nuclear fuel in a geologic repository. So, why is it not recycled? It turns out that separating usable versus unusable parts of spent nuclear fuel is complicated.
“Spent nuclear fuel contains roughly half of the periodic table. So, from a chemistry standpoint, there’s a lot going on,” said Gregg Lumetta, PNNL chemist and laboratory fellow. “And to reduce proliferation risk, it is best if pure plutonium is not produced at any point in the separation process.”
May 16, 2021
Clocking Electron Movements Inside an Atom – Shutter Speed of a Millionth of a Billionth of a Second
Posted by Quinn Sena in categories: biological, chemistry, particle physics
Scientists dramatically enhance the achievable resolution at free-electron lasers with a new technique.
Hard X-ray free-electron lasers (XFELs) have delivered intense, ultrashort X-ray pulses for over a decade. One of the most promising applications of XFELs is in biology, where researchers can capture images down to the atomic scale even before the radiation damage destroys the sample. In physics and chemistry, these X-rays can also shed light on the fastest processes occurring in nature with a shutter speed lasting only one femtosecond – equivalent to a millionth of a billionth of a second.
However, on these minuscule timescales, it is extremely difficult to synchronize the X-ray pulse that sparks a reaction in the sample on the one hand and the laser pulse which ‘observes’ it on the other. This problem is called timing jitter, and it is a major hurdle in ongoing efforts to perform time-resolved experiments at XFELs with ever-shorter resolution.
May 16, 2021
Genetically engineered grass cleanses soil of toxic pollutants left
Posted by Jason Blain in categories: biotech/medical, chemistry, genetics, military
Large swaths of U.S. military land are covered with munitions components, including the explosive chemical RDX. This molecule is toxic to people and can cause cancer. It also doesn’t naturally break down and can contaminate groundwater. Now researchers have genetically engineered a grass commonly used to fight soil erosion so that it can remove RDX from the soil, according to a new paper published May 3 in Nature Biotechnology.
A team, which includes researchers from the University of Washington, demonstrated that over the course of three years, a genetically engineered switchgrass could break down an explosive chemical in…