Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: chemistry – Page 80

AI training method can drastically shorten time for calculations in quantum mechanics

The close relationship between AI and highly complicated scientific computing can be seen in the fact that both the 2024 Nobel Prizes in Physics and Chemistry were awarded to scientists for devising AI for their respective fields of study. KAIST researchers have now succeeded in dramatically shortening the calculation time of highly sophisticated quantum mechanical computer simulations by predicting atomic-level chemical bonding information distributed in 3D space using a novel approach to teach AI.

Predicting Droplet Size in Sprays

A new model of liquid sprays reveals the mechanisms behind droplet formation—providing important information for eventually controlling the droplet sizes in, for example, home cleaning sprays.

Spraying a cleaning product on a kitchen counter may be a mundane task, but it embodies a wide-reaching environmental problem. In atomized sprays like these, the largest droplets land on the surface as desired, while the smallest ones drift away and evaporate, wasting liquid and contaminating the surroundings. As Isaac Jackiw of the University of Alberta, Canada, says, “If you have an intuitive understanding of where the different sizes come from, then you can start to imagine specific targeted approaches for preventing unwanted sizes.” He and his colleagues have now developed a physics-based model that predicts the distribution of droplet size in sprays emitted from a nozzle. Jackiw presented the work at the Canadian Chemical Engineering Conference in Toronto this month.

In classical models of aerodynamic droplet breakup, airflow hits a liquid and causes it to explode into droplets. To explain the average droplet size, theorists have often focused on a single, dominant mechanism. But these methods have not been able to directly predict the distribution in droplet sizes, Jackiw says. His approach can estimate the size distribution by incorporating several different mechanisms, each of which contributes droplets in a particular size range.

Measurement of Ascorbic Acid Samples’ Optical Rotation via an Improvised Polarimeter for Purity Assessment

The polarization of light finds practical application in physics and chemistry through the optical activity phenomenon, where polarimeters play a crucial role. This research builds on the improvised polarimeter designed by Kvittingen and Sjursnes, implemented with relevant modifications, to measure optical rotations of over-the-counter ascorbic acid samples. The study aims to assess the purity of two brands of ascorbic acid through polarimetry, comparing the calculated specific rotation with the literature values and supplementing the characterization with melting point determination. The constructed polarimeter, assembled using Lego bricks, provides an affordable alternative for educational purposes, addressing the challenges observed in the accessibility of commercial polarimeters for classroom demonstrations. The methodology encompasses pre-experiment steps involving polarimeter construction, the experiment utilizing polarimetry and complementary melting point determination, and post-experiment analysis to determine specific rotation from the measured optical rotations. Results indicate that Brand X exhibited specific rotations close to theoretical values, inferring high purity. Conversely, Brand Y shows significant deviations, suggesting potential impurities. These conclusions are supported by melting point data. The comprehensive approach combining polarimetry and melting point determination enhances the reliability of purity assessments, showcasing the effectiveness of the improvised polarimeter in practical applications.

R J M Felicidario and R M delos Santos 2024 J. Phys.: Conf. Ser. 2,871 012009.

Unlocking Nature’s Secret Weapon: Fungus That Fights Cancer

New research into a chemical from a caterpillar fungus, known for its potential as a cancer treatment, has shown how it interacts with genes to disrupt cell growth signals. This finding marks a promising step toward developing new cancer drugs.

The chemical, called cordycepin, interrupts overactive cell growth signals common in cancer, potentially offering a treatment approach that could be gentler on healthy tissues compared to many existing therapies.

Caterpillar fungus: a potential cancer treatment.

Advanced sensing tech can detect lung cancer in your exhaled breath

Researchers have developed a nanoscale sensor that detects lung cancer simply by analyzing the levels of a chemical called isoprene in your breath. The team believes its breakthrough could unlock a non-invasive, low-cost method to catch the disease early, and potentially save a lot of lives.

When the human body breaks down fat in a process called lipolytic cholesterol metabolism, isoprene is released in exhaled breath. As it turns out, a decline in isoprene can indicate the presence of lung cancer. The team, led by researchers at China’s Zhejiang University, leveraged this insight through its work and developed an innovative gas sensing material to create a screening process.

The challenge with spotting biomarkers in breath is that your system needs to be able to differentiate between volatile chemicals, withstand the natural humidity of exhaled breath, and detect tiny quantities of specific chemicals. In the case of isoprene, you’d need sensors capable of detecting levels of the chemical in the parts-per-billion (ppb) range.

Scientists discover molecules that store much of the carbon in space

The discovery of pyrene in this far-off cloud, which is similar to the collection of dust…

A team led by researchers at MIT has discovered that a distant interstellar cloud contains an abundance of pyrene, a type of large, carbon-containing molecule known as a polycyclic aromatic hydrocarbon (PAH).

The discovery of pyrene in this far-off cloud, which is similar to the collection of dust and gas that eventually became our own solar system, suggests that pyrene may have been the source of much of the carbon in our solar system. That hypothesis is also supported by a recent finding that samples returned from the near-Earth asteroid Ryugu contain large quantities of pyrene.

“One of the big questions in star and planet formation is: How much of the chemical inventory from that early molecular cloud is inherited and forms the base components of the solar system? What we’re looking at is the start and the end, and they’re showing the same thing. That’s pretty strong evidence that this material from the early molecular cloud finds its way into the ice, dust, and rocky bodies that make up our solar system,” says Brett McGuire, an assistant professor of chemistry at MIT.

Plant-animal hybrid cells make solar-powered tissues, organs or meat

Scientists in Japan have created hybrid plant-animal cells, essentially making animal cells that can gain energy from sunlight like plants. The breakthrough could have major benefits for growing organs and tissues for transplant, or lab-grown meat.

Animal and plant cells have different energy-producing structures inside them. For animals, that’s mitochondria, which convert chemical energy from food into a form that our cells can use. Plants and algae, meanwhile, use chloroplasts, which perform photosynthesis to generate energy from sunlight to power their cells.

In a new study led by the University of Tokyo, the team inserted chloroplasts into animal cells, and found that they continued to perform photosynthetic functions for at least two days. The chloroplasts were sourced from red algae, while the animal cells were cultured from hamsters.

Saturday Citations: On chimpanzee playwrights; the nature of dark energy; deep-diving Antarctic seals

This week, researchers reported the world’s second-tiniest toad, winning the silver in the Brachycephalus contest. Chemists at UCLA disproved a 100-year-old organic chemistry rule. And researchers in Kenya report that elephants don’t like bees, which could be a conservation boon (for the elephants. And maybe also the bees?). Additionally, scientists addressed an old thought experiment about monkeys and the theater, physicists correlated dark energy with the black hole population in the universe, and a group of Antarctic seals were found to be highly strategic and also adorable: