Researchers in the Technion Department of Materials Science and Engineering have succeeded in changing a material’s electrical properties by vacating an oxygen atom from the original structure. Possible applications include electronic-device miniaturization and radiation detection.
What do ultrasound imaging of a fetus, cellular mobile communication, micro motors, and low-energy-consumption computer memories have in common? All of these technologies are based on ferroelectric materials, which are characterized by a strong correlation between their atomic structure and the electrical and mechanical properties.
Technion–Israel Institute of Technology researchers have succeeded in changing the properties of ferroelectric materials by vacating a single oxygen atom from the original structure. The breakthrough could pave the way for the development of new technologies. The research was headed by Assistant Professor Yachin Ivry of the Department of Materials Science and Engineering, accompanied by postdoctoral researcher Dr. Hemaprabha Elangovan and Ph.D. student Maya Barzilay, and was published in ACS Nano. It is noted that engineering an individual oxygen vacancy poses a considerable challenge due to the light weight of oxygen atoms.
The combination of techniques is now delivering highly polarized proton beams to collide inside STAR.
When they analyze results from these collisions, STAR physicists will be looking for differences in the numbers of certain particles emerging to the left and right of the polarized protons’ upward pointing direction.
If the finding really is the result of new fundamental particles then it will finally be the breakthrough that physicists have been yearning for for decades.
When CERN’s gargantuan accelerator, the Large Hadron Collider (LHC), fired up ten years ago, hopes abounded that new particles would soon be discovered that could help us unravel physics’ deepest mysteries. Dark matter, microscopic black holes, and hidden dimensions were just some of the possibilities. But aside from the spectacular discovery of the Higgs boson, the project has failed to yield any clues as to what might lie beyond the standard model of particle physics, our current best theory of the micro-cosmos.
So our new paper from LHCb, one of the four giant LHC experiments, is likely to set physicists’ hearts beating just a little faster. After analyzing trillions of collisions produced over the last decade, we may be seeing evidence of something altogether new – potentially the carrier of a brand new force of nature.
But the excitement is tempered by extreme caution. The standard model has withstood every experimental test thrown at it since it was assembled in the 1970s, so to claim that we’re finally seeing something it can’t explain requires extraordinary evidence.
The previously elusive methanediol molecule of importance to the organic, atmospheric science and astrochemistry communities has been synthetically produced for the first time by University of Hawaiʻi at Mānoa researchers. Their discovery and methods were published in Proceedings of the National Academy of Sciences on December 30.
Methanediol is also known as formaldehyde monohydrate or methylene glycol. With the chemical formula CH2(OH)2, it is the simplest geminal diol, a molecule which carries two hydroxyl groups (OH) at a single carbon atom. These organic molecules are suggested as key intermediates in the formation of aerosols and reactions in the ozone layer of the atmosphere.
The research team—consisting of Department of Chemistry Professor Ralf Kaiser, postdoctoral researchers Cheng Zhu, N. Fabian Kleimeier and Santosh Singh, and W.M. Keck Laboratory in Astrochemistry Assistant Director Andrew Turner—prepared methanediol via energetic processing of extremely low temperature ices and observed the molecule through a high-tech mass spectrometry tool exploiting tunable vacuum photoionization (the process in which an ion is formed from the interaction of a photon with an atom or molecule) in the W.M. Keck Laboratory in Astrochemistry. Electronic structure calculations by University of Mississippi Associate Professor Ryan Fortenberry confirmed the gas phase stability of this molecule and demonstrated a pathway via reaction of electronically excited oxygen atoms with methanol.
LCLS-II will be able to produce images of atoms a million times a second.
Scientists at the Department of Energy’s SLAC National Accelerator Laboratory are putting the finishing touches on what will become the world’s brightest laser. Called the Linac Coherent Light Source II (LCLS-II), it will be 10,000 times brighter than the brightest laser before itself, once it becomes operational.
Currently, under construction about 30 feet (9 meters) underground close to Stanford University, the laser promises to help physicists unlock some of the fundamental unknowns about our universe. The laser apparatus extends for about 2 miles (3.2 km) in a specially excavated tunnel.
Its predecessor, Linac Coherent Light Source I (LCLS-I) went live in 2009 and is able to create a beam capable of 120 light pulses a second. LCLS-II, however, crushes this record by being able to produce 1 million pulses per second.
“I think it’s absolutely fair to say that the LCLS-II will usher in a new era of science,” Dr. James Cryan, a staff scientist at SLAC told CNET in an exclusive tour of the new facility.
High energy density (HED) laboratory plasmas are perhaps the most extreme states of matter ever produced on Earth. Normal plasmas are one of the four basic states of matter, along with solid, gases, and liquids. But HED plasmas have properties not found in normal plasmas under ordinary conditions. For example, matter in this state may simultaneously behave as a solid and a gas. In this state, materials that normally act as insulators for electrical charges instead become conductive metals. To create and study HED plasmas, scientists compress materials in solid or liquid form or bombard them with high energy particles or photons.
While working with helium nanodroplets, scientists at the Department of Ion Physics and Applied Physics led by Fabio Zappa and Paul Scheier have come across a surprising phenomenon: When the ultracold droplets hit a hard surface, they behave like drops of water. Ions with which they were previously doped thus remain protected on impact and are not neutralized.
At the Department of Ion Physics and Applied Physics, Paul Scheier’s research group has been using helium nanodroplets to study ions with methods of mass spectrometry for around 15 years. Using a supersonic nozzle, tiny, superfluid helium nanodroplets can be produced with temperatures of less than one degree Kelvin. They can very effectively be doped with atoms and molecules. In the case of ionized droplets, the particles of interest are attached to the charges, which are then measured in the mass spectrometer. During their experiments, the scientists have now stumbled upon an interesting phenomenon that has fundamentally changed their work. “For us, this was a gamechanger,” says Fabio Zappa from the nano-bio-physics team. “Everything at our lab is now done with this newly discovered method.” The researchers have now published the results of their studies in Physical Review Letters.
Digitization results in a high energy consumption. In industrialized countries, information technology presently has a share of more than 10% in total power consumption. The transistor is the central element of digital data processing in computing centers, PCs, smartphones, or in embedded systems for many applications from the washing machine to the airplane. A commercially available low-cost USB memory stick already contains several billion transistors. In the future, the single-atom transistor developed by Professor Thomas Schimmel and his team at the Institute of Applied Physics (APH) of KIT might considerably enhance energy efficiency in information technology. “This quantum electronics element enables switching energies smaller than those of conventional silicon technologies by a factor of 10,000,” says physicist and nanotechnology expert Schimmel, who conducts research at the APH, the Institute of Nanotechnology (INT), and the Material Research Center for Energy Systems (MZE) of KIT. Earlier this year, Professor Schimmel, who is considered the pioneer of single-atom electronics, was appointed Co-Director of the Center for Single-Atom Electronics and Photonics established jointly by KIT and ETH Zurich.
In Advanced Materials, the KIT researchers present the transistor that reaches the limits of miniaturization. The scientists produced two minute metallic contacts. Between them, there is a gap as wide as a single metal atom. “By an electric control pulse, we position a single silver atom into this gap and close the circuit,” Professor Thomas Schimmel explains. “When the silver atom is removed again, the circuit is interrupted.” The world’s smallest transistor switches current through the controlled reversible movement of a single atom. Contrary to conventional quantum electronics components, the single-atom transistor does not only work at extremely low temperatures near absolute zero, i.e.-273°C, but already at room temperature. This is a big advantage for future applications.
The single-atom transistor is based on an entirely new technical approach. The transistor exclusively consists of metal, no semiconductors are used. This results in extremely low electric voltages and, hence, an extremely low energy consumption. So far, KIT’s single-atom transistor has applied a liquid electrolyte. Now, Thomas Schimmel and his team have designed a transistor that works in a solid electrolyte. The gel electrolyte produced by gelling an aqueous silver electrolyte with pyrogenic silicon dioxide combines the advantages of a solid with the electrochemical properties of a liquid. In this way, both safety and handling of the single-atom transistor are improved.
The COVID-19 pandemic highlighted the devastating impact of acute lung inflammation (ALI), which is part of the acute respiratory distress syndrome (ARDS) that is the dominant cause of death in COVID-19. A potential new route to the diagnosis and treatment of ARDS comes from studying how neutrophils—the white blood cells responsible for detecting and eliminating harmful particles in the body—differentiate what materials to uptake by the material’s surface structure, and favor uptake of particles that exhibit “protein clumping,” according to new research from the Perelman School of Medicine at the University of Pennsylvania. The findings are published in Nature Nanotechnology.
Researchers investigated how neutrophils are able to differentiate between bacteria to be destroyed and other compounds in the bloodstream, such as cholesterol particles. They tested a library consisting of 23 different protein-based nanoparticles in mice with ALI which revealed a set of “rules” that predict uptake by neutrophils. Neutrophils don’t take up symmetrical, rigid particles, such as viruses, but they do take up particles that exhibited “protein clumping,” which the researchers call nanoparticles with agglutinated protein (NAPs).
“We want to utilize the existing function of neutrophils that identifies and eliminates invaders to inform how to design a ‘Trojan horse’ nanoparticle that overactive neutrophils will intake and deliver treatment to alleviate ALI and ARDS,” said study lead author Jacob Myerson, Ph.D., a postdoctoral research fellow in the Department of Systems Pharmacology and Translational Therapeutics. “In order to build this ‘Trojan horse’ delivery system, though, we had to determine how neutrophils identify which particles in the blood to take up.”
Demonstrating that a material thought to be always chemically inert, hexagonal boron nitride (hBN), can be turned chemically active holds potential for a new class of catalysts with a wide range of applications, according to an international team of researchers.
HBN is a layered material and monolayers can be exfoliated like in graphene 0, another two-dimensional material. However, there is a key difference between the two.
“While hBN shares similar structure as graphene, the strong polar bonds between the boron and nitride atoms makes hBN unlike graphene in that it is chemically inert and thermally stable at high temperature,” said Yu Lei, postdoctoral scholar in physics at Penn State and first co-author in the study published in Materials Today.