Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics – Page 16

First-of-its-kind measurement may help physicists learn about gluons, which hold together nuclei in atoms

A team of physicists has embarked on a journey where few others have gone: into the glue that binds atomic nuclei. The resultant measurement, which was extracted from experimental data taken at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, is the first of its kind and will help physicists image particles called gluons.

The paper revealing the results is published and featured as an editor’s suggestion in Physical Review Letters.

Gluons mediate the strong force that “glues” together quarks, another type of subatomic particle, to form the protons and neutrons situated at the center of atoms of ordinary matter. While previous measurements have allowed researchers to learn about the distribution of gluons in solitary protons or neutrons, they know less about how gluons behave inside protons or neutrons bound in nuclei.

A new molecular model of bilayer graphene with higher semiconducting properties

Juan Casado Cordón, Professor of Physical Chemistry at the University of Malaga, considers graphene—an infinite layer of carbon atoms—as one of the greatest discoveries of the last 20 years due to its “unique properties” such as high electrical and thermal conductivity or its great flexibility and, also, resistance. Qualities that become exceptional, he explains, with a recently found evolution consisting in joining two layers of this material—bilayer graphene.

Researchers from the University of Malaga, led by Casado Cordón, and from the Complutense University, under the coordination of Professor Nazario Martín, have taken a step further and created an unprecedented molecular model of that is capable of controlling rotation, which in turn allows controlling conductivity and achieving “potentially spectacular semiconducting properties.”

The result is a new model molecule of bilayer graphene. “By designing covalently bound molecular nanographenes we can simulate the search for the magic angle between graphene-like sheets, which is where semiconductivity is achieved, a key property in, for example, the construction of transistors, the basic units of computers,” explains this scientist from the Faculty of Science. This finding has been published in Nature Chemistry.

Smart phonon control boosts efficiency in eco-friendly thermoelectric material

A research team has discovered how to make a promising energy-harvesting material much more efficient—without relying on rare or expensive elements. The material, called β-Zn4Sb3, is a tellurium-free thermoelectric compound that can convert waste heat into electricity.

In their study published in Advanced Science, scientists used advanced neutron scattering techniques to peek inside the crystal and found something surprising: tiny heat vibrations (called phonons) were being disrupted by “rattling” atoms inside the structure. This phenomenon, known as avoided crossing, dramatically slowed down how heat travels through the material.

Thanks to this effect, the material’s dropped to extremely low levels—great news for . Even better, the researchers found that the single-crystal version of this material also conducts electricity better than its polycrystalline counterpart, reaching a high power conversion efficiency of 1.4%.

Porphyrin-based nanosheets capture viruses; researchers work to improve air flow for mask applications

The COVID-19 pandemic increased public awareness of the importance of mask use for personal protection. However, when the mesh size of mask fabrics is small enough to capture viruses, which are usually around one hundred nanometers in size, the fabric typically also restricts air flow, resulting in user discomfort. Researchers from Japan have now developed a new filter material that effectively captures nanoparticles, although further improvements are needed to make it suitable for comfortable mask use.

In a study published this month in Materials Advances, researchers from the Institute of Industrial Science at the University of Tokyo have developed a filter capable of capturing nanoparticles such as viruses. While the filter demonstrates high filtration efficiency, its airflow resistance is currently higher than the standards required for face masks, indicating that additional development is necessary before it can be used for personal protective equipment.

The filter is constructed from nanosheets consisting of an ordered mesh composed of porphyrins, which are flat, ring-shaped molecules with a central hole. The in the porphyrin molecules are suitably sized to allow the easy passage of the small gas molecules in air while blocking the movement of larger particles, such as viruses. The nanosheets are then supported on a fabric modified with nanofibers containing pores of several hundred nanometers to form the filter.

Closing the gaps—MXene-coated air filters show enhanced performance and reusability

Despite improvements to air filtration technology in the aftermath of the COVID-19 pandemic, some of the smallest particles—those of automobile and factory emissions—can still make their way through less efficient, but common filters. An interdisciplinary team of researchers from Drexel University’s College of Engineering have introduced a new way to improve textile-based filters by coating them with a type of two-dimensional nanomaterial called MXene.

Recently published in the journal C—Journal of Carbon Research, the team’s research reports that a non-woven polyester textile—a low-cost material with low filtration efficiency—coated with a thin layer of MXene nanomaterial can turn it into a potent filter capable of pulling some of the finest nanoparticles from the air.

“It can be challenging for common filters to contend with particles less than 100 nanometers, which include those emitted by industrial processes and automobiles,” said Michael Waring, Ph.D., a professor in Drexel’s College of Engineering, and co-author of the research. “Being able to augment a filter, through a simple coating process, to make it effective against these emissions is a significant development.”