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Archive for the ‘chemistry’ category: Page 4

May 16, 2024

Scientists demonstrate the survival of quantum coherence in a chemical reaction involving ultracold molecules

Posted by in categories: chemistry, particle physics, quantum physics

If you zoom in on a chemical reaction to the quantum level, you’ll notice that particles behave like waves that can ripple and collide. Scientists have long sought to understand quantum coherence, the ability of particles to maintain phase relationships and exist in multiple states simultaneously; this is akin to all parts of a wave being synchronized. It has been an open question whether quantum coherence can persist through a chemical reaction where bonds dynamically break and form.

May 16, 2024

Wavefunction matching for solving quantum many-body problems

Posted by in categories: chemistry, particle physics, quantum physics

Strongly interacting systems play an important role in quantum physics and quantum chemistry. Stochastic methods such as Monte Carlo simulations are a proven method for investigating such systems. However, these methods reach their limits when so-called sign oscillations occur. This problem has now been solved by an international team of researchers from Germany, Turkey, the USA, China, South Korea and France using the new method of wavefunction matching. As an example, the masses and radii of all nuclei up to mass number 50 were calculated using this method. The results agree with the measurements, the researchers now report in the journal “Nature.”

All matter on Earth consists of tiny particles known as atoms. Each atom contains even smaller particles: protons, neutrons and electrons. Each of these particles follows the rules of quantum mechanics. Quantum mechanics forms the basis of quantum many-body theory, which describes systems with many particles, such as atomic nuclei.

One class of methods used by nuclear physicists to study atomic nuclei is the ab initio approach. It describes complex systems by starting from a description of their elementary components and their interactions. In the case of nuclear physics, the elementary components are protons and neutrons. Some key questions that ab initio calculations can help answer are the binding energies and properties of atomic nuclei and the link between nuclear structure and the underlying interactions between protons and neutrons.

May 16, 2024

Scientists control daily biological clock of algae, advancing biomedicine

Posted by in categories: biotech/medical, chemistry

Carl H. Johnson, Cornelius Vanderbilt Professor of Biological Sciences, along with a team of Vanderbilt scientists, have succeeded in adjusting the daily biological clock of cyanobacteria, making the blue-green algae a more prolific producer of renewable fuels, chemicals, and pharmaceuticals like insulin.

May 16, 2024

Finding credible pathways to net-zero emissions: The challenge of scaling up an emerging electrification technology

Posted by in categories: chemistry, energy, sustainability

Chemical and material engineering professor, Adnan Khan, has spent the past 15 years focusing his research on developing sustainable technologies aimed at decarbonizing our energy systems. “This is the most important challenge we face today. We owe this to our future generations,” he says.

May 16, 2024

New method of wavefunction matching helps solve quantum many-body problems

Posted by in categories: chemistry, particle physics, quantum physics

Strongly interacting systems play an important role in quantum physics and quantum chemistry. Stochastic methods such as Monte Carlo simulations are a proven method for investigating such systems. However, these methods reach their limits when so-called sign oscillations occur.

This problem has now been solved by an international team of researchers from Germany, Turkey, the U.S., China, South Korea and France using the new method of wavefunction matching. As an example, the masses and radii of all nuclei up to mass number 50 were calculated using this method. The results agree with the measurements, the researchers now report in the journal Nature.

All matter on Earth consists of tiny particles known as atoms. Each atom contains even smaller particles: protons, neutrons and electrons. Each of these particles follows the rules of quantum mechanics. Quantum mechanics forms the basis of quantum many-body theory, which describes systems with many particles, such as .

May 15, 2024

Repurposed beer yeast encapsulated in hydrogels may offer a cost-effective way to remove lead from water

Posted by in categories: chemistry, engineering, particle physics

Every year, beer breweries generate and discard thousands of tons of surplus yeast. Researchers from MIT and Georgia Tech have now come up with a way to repurpose that yeast to absorb lead from contaminated water.

Through a process called biosorption, yeast can quickly absorb even trace amounts of lead and other heavy metals from water. The researchers showed that they could package the yeast inside hydrogel capsules to create a filter that removes lead from water. Because the yeast cells are encapsulated, they can be easily removed from the water once it’s ready to drink.

“We have the hydrogel surrounding the free yeast that exists in the center, and this is porous enough to let water come in, interact with yeast as if they were freely moving in water, and then come out clean,” says Patricia Stathatou, a former postdoc at the MIT Center for Bits and Atoms, who is now a research scientist at Georgia Tech and an incoming assistant professor at Georgia Tech’s School of Chemical and Biomolecular Engineering.

May 15, 2024

Multi-scale, nanomaterial-based ice inhibition platform enables full-cycle cryogenic protection for mouse oocytes

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

Safe and high-quality fertility preservation is of growing significance for women in clinical trials. Current primary methods for cryopreserving human oocytes are slow freezing and vitrification, but existing techniques pose risks of biochemical toxicity and are restricted in large-scale clinical practice.

May 14, 2024

Bionanomachine Breakthrough: A Master Key for Sustainable Chemistry

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

Scientists at the Paul Scherrer Institute (PSI) have for the first time precisely characterized the enzyme styrene oxide isomerase, which can be used to produce valuable chemicals and drug precursors in an environmentally friendly manner. The study appears today in the journal Nature Chemistry.

Enzymes are powerful biomolecules that can be used to produce many substances at ambient conditions. They enable “green” chemistry, which reduces environmental pollution resulting from processes used in synthetic chemistry. One such tool from nature has now been characterized in detail by PSI researchers: the enzyme styrene oxide isomerase. It is the biological version of the Meinwald reaction, an important chemical reaction in organic chemistry.

“The enzyme, discovered decades ago, is made by bacteria,” says Richard Kammerer of PSI’s Biomolecular Research Laboratory. His colleague Xiaodan Li adds: “But because the way it functions was not known, its practical application has been limited up to now.” The two researchers and their team have elucidated the structure of the enzyme as well as the way it works.

May 11, 2024

GIST researchers develop nanotechnology for quickly creating wafer-scale nanoparticle monolayers

Posted by in categories: chemistry, nanotechnology

Adopting electrostatic assembly processes where the nanoparticles attach themselves to an oppositely charged surface is a possible way out of this dilemma. Once a monolayer is formed, the nanoparticles self-limit further assembly by repelling other similarly charged nanoparticles away from the surface. Unfortunately, this process can be very time-consuming.

While artificial methods struggle with these drawbacks, underwater adhesion processes found in nature have evolved into unique strategies to overcome this problem. In this regard, a team of researchers from Gwangju Institute of Science and Technology, led by Ph.D. student Doeun Kim (first author) and Assistant Professor Hyeon-Ho Jeong (corresponding author), developed a “mussel-inspired” one-shot nanoparticle assembly technique that transports materials from water in microscopic volumes to 2-in. wafers in 10 seconds, while enabling 2D mono-layered assembly with excellent surface coverage of around 40%. Their work was published in Advanced Materials on April 18, 2024, and highlighted as a frontispiece.

“Our key approach to overcome the existing challenge came from observing how mussels reach the target surface against water. We saw that mussels simultaneously radiate amino acids to dissociate water molecules on the surface, enabling swift attachment of the chemical adhesive on the target surface. We realized that an analogous situation where we introduce excess protons to remove hydroxyl groups from the target surface, thus increasing the electrostatic attraction force between the nanoparticles and the surface and accelerating the assembly process,” said Ms. Kim when asked about the motivation behind the unique nature-inspired approach.

May 11, 2024

Discovering optimal conditions for mass production of ultraviolet holograms

Posted by in categories: chemistry, engineering, holograms

Professor Junsuk Rho from the Department of Mechanical Engineering, Chemical Engineering, and Electrical Engineering, Hyunjung Kang and Nara Jeon, PhD candidates, from Department of Mechanical Engineering and Dongkyo Oh, a PhD student, from the Department of Mechanical Engineering at Pohang University of Science and Technology (POSTECH) successfully conducted a thorough quantitative analysis. Their aim is to determine the ideal printing material for crafting ultraviolet metasurfaces.

Their findings featured in the journal Microsystems & Nanoengineering (“Tailoring high-refractive-index nanocomposites for manufacturing of ultraviolet metasurfaces”).

Diagram illustrating the composition of nanocomposites for ultraviolet metasurface fabrication. (Top) Diagram illustrating the ZrO 2 nanocomposite’s role in achieving high transfer fidelity ultraviolet metaholograms. (Bottom) Comparison of UV holograms under various solvent conditions. (Image: POSTECH)

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