Toggle light / dark theme

Whenever and wherever stars are born, which occurs whenever clouds of gas sufficiently collapse under their own gravity, they come in a wide variety of sizes, colors, temperatures, and masses. The largest, bluest, most massive stars contain the greatest amounts of nuclear fuel, but perhaps paradoxically, those stars are actually the shortest lived. The reason is straightforward: in any star’s core, where nuclear fusion occurs, it only occurs wherever temperatures exceed 4 million K, and the higher the temperature, the greater the rate of fusion.

So the most massive stars might have the most fuel available at the start, but that means they shine brightly as they burn through their fuel quickly. In particular, the hottest regions in the core will exhaust their fuel the fastest, leading the most massive stars to die the most quickly. The best method we have for measuring “How old is a collection of stars?” is to examine globular clusters, which form stars in isolation, often all at once, and then never again. By looking at the cooler, fainter stars that remain (and the lack of hotter, bluer, brighter, more massive stars), we can state with confidence that the Universe must be at least ~12.5–13.0 billion years old.

The widespread adoption of electric vehicles greatly relies on the development of robust and fast-charging battery technologies that can support their continuous operation for long periods of time. One proposed energy storage solution to improve the endurance of electric vehicles entails the use of so-called structural batteries.

Structural batteries are batteries that can serve two purposes, acting both as structural components of vehicles and solutions. Instead of being external components that are added to an electronic or electric device, these batteries are thus directly embedded into the structure.

Researchers at Shanghai University and their collaborators recently devised a promising strategy to fabricate highly performing structural batteries with customizable geometric configurations. Their strategy, outlined in a paper published in Composites Science and Technology, enables the 3D-printing of structural lithium-ion batteries for different geometrical configurations.

Lithium-metal batteries could exhibit significantly higher energy densities than lithium-ion batteries, which are the primary battery technology on the market today. Yet lithium-metal cells also typically have significant limitations, the most notable of which is a short lifespan.

Researchers at University of Science and Technology of China and other institutes recently introduced a new electrolyte design that could be used to develop highly performing lithium-metal pouch cells with longer lifespans. This electrolyte, presented in a paper in Nature Energy, has a unique nanometer-scale solvation structure, with pairs of ions densely packed together into compact ion-pair aggregates (CIPA).

“The primary objectives of our recent work are to markedly accelerate the practical applications of lithium-metal batteries and offer deep mechanistic understandings of this complicated system,” Prof. Shuhong Jiao, co-author of the paper, told Tech Xplore.

Right off the bat, one of the biggest improvements is the weight of the 4,680 shell itself – down to 49g from the 70g weight of a gen 1 cell. Tesla has essentially optimized the shell, making it thinner, and reducing its internal complexity. They do this by welding the tabless electrode to the cell cap.

That weight reduction is significant – at the battery pack level, the Cybertruck has 1,344 cells – which means that it reduces 28.2kg or 62.1lb of the overall pack weight. But rather than leaving that space empty, Tesla has instead filled that weight with more battery material. Calculated, that’s about a 10% increase in overall pack energy density.

The Limiting Factor intends to release another video looking at the energy density of the Cybercell and the detailed specs of the 4,680 cell. We’ll be on the lookout for both of those videos in the coming weeks as they could reveal additional information on Tesla’s 4,680 Gen 2 cells. We’re interested in how the Cybercell shapes up in comparison to the previous 4,680 cells – which were pulled from production after the 4680 Model Y.

“This breakthrough helps us better understand and study the fascinating world of quantum physics,” he says.

The fluorescent nanodiamonds, with an average diameter of about 750 nm, were produced through high-pressure, high-temperature synthesis. These diamonds were irradiated with high-energy electrons to create nitrogen-vacancy color centers, which host electron spin qubits.

When illuminated by a green laser, they emitted red light, which was used to read out their electron spin states. An additional infrared laser was shone at the levitated nanodiamond to monitor its rotation. Like a disco ball, as the nanodiamond rotated, the direction of the scattered infrared light changed, carrying the rotation information of the nanodiamond.

Due to its excellent material properties and its adaptability to gallium nitride (GaN), AlYN has enormous potential for use in energy-efficient high-frequency and high-performance electronics for information and communications technology.

Aluminum yttrium nitride (AlYN) has attracted the interest of many research groups around the world due to its outstanding material properties. However, the growth of the material has been a major challenge. Until now, AlYN could only be deposited by magnetron sputtering.

Researchers at the Fraunhofer Institute for Applied Solid State Physics IAF have now succeeded in fabricating the new material using metal-organic chemical vapor deposition (MOCVD) technology, thus enabling the development of new, diverse applications.

Variable renewables cannot, by themselves, reliably supply all of our electricity and heat. But we can change our demand for energy supply through targeted energy efficiency and smart demand management.

The ISP focuses on electricity supply, so it does not effectively address gas-related factors such as the impact of efficient building electrification on electricity demand. Assumptions that electrification will dramatically increase electricity demand are risky.

A lot of gas technologies are far less efficient than many believe, and deliver heat at temperatures higher than processes actually require. And gas equipment can use significant amounts of electricity for fans, pumps, controls and other functions.

Researchers at the University of Maryland genetically modified poplar trees to produce high-performance, structural wood without the use of chemicals or energy-intensive processing. Made from traditional wood, engineered wood is often seen as a renewable replacement for traditional building materials like steel, cement, glass and plastic. It also has the potential to store carbon for a longer time than traditional wood because it can resist deterioration, making it useful in efforts to reduce carbon emissions.

But the hurdle to true sustainability in engineered wood is that it requires processing with volatile chemicals and a significant amount of energy, and produces considerable waste. The researchers edited one gene in live poplar trees, which then grew wood ready for engineering without processing.

The research was published online on August 12, 2024, in the Journal Matter.