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Shut Up About the Batteries: The Key to a Better Electric Car Is a Lighter Motor

The trick is to make a motor that can tweak its magnetic fields to run more efficiently

11 min read
Photo: Karlsruhe Institute of Technology
Photo: Karlsruhe Institute of Technology

/image/MjkxNTcyNQ.jpeg Keep On Turning: The authors’ motor represents an advance on another design—one that did not use magnets to shift the field. Photos: Karlsruhe Institute of Technology

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A Transistor for Sound Points Toward Whole New Electronics

“Topological” acoustic transistor suggests circuits with dissipationless flow of electricity or light

3 min read
Model of a honeycomb lattice

Model of a honeycomb lattice that serves as the basis for a "transistor" of sound waves—whose design suggests new kinds of transistors of light and electricity, made from so-called topological materials. Electrons in a topological transistor, it is suspected, would flow without any resistance.

Hoffman Lab/Harvard SEAS

Potential future transistors that consume far less energy than current devices may rely on exotic materials called "topological insulators" in which electricity flows across only surfaces and edges, with virtually no dissipation of energy. In research that may help pave the way for such electronic topological transistors, scientists at Harvard have now invented and simulated the first acoustic topological transistors, which operate with sound waves instead of electrons.

Topology is the branch of mathematics that explores the nature of shapes independent of deformation. For instance, an object shaped like a doughnut can be deformed into the shape of a mug, so that the doughnut's hole becomes the hole in the cup's handle. However, the object couldn't lose the hole without changing into a fundamentally different shape.

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Taking Cosmology to the Far Side of the Moon

New Chinese program plans to use satellites in lunar orbit to study faint signals from early universe

3 min read
crescent moon
Darwin Fan/Getty Images

A team of Chinese researchers are planning to use the moon as a shield to detect otherwise hard-to-observe low frequencies of the electromagnetic spectrum and open up a new window on the universe. The Discovering the Sky at the Longest Wavelengths (DSL) mission aims to seek out faint, low-frequency signals from the early cosmos using an array of 10 satellites in lunar orbit. If it launches in 2025 as planned, it will offer one of the very first glimpses of the universe through a new lens.

Nine “sister” spacecraft will make observations of the sky while passing over the far side of the moon, using our 3,474-kilometer-diameter celestial neighbor to block out human-made and other electromagnetic interference. Data collected in this radio-pristine environment will, according to researchers, be gathered by a larger mother spacecraft and transmitted to Earth when the satellites are on the near side of the moon and in view of ground stations.

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EP29LPSP: Applications in Plasma Physics, Astronomy, and Highway Engineering

Ideal for demanding cryogenic environments, two-part EP29LPSP can withstand temperatures as low as 4K

3 min read

Since its introduction in 1978, Master Bond EP29LPSP has been the epoxy compound of choice in a variety of challenging applications. Ideal for demanding cryogenic environments, two-part EP29LPSP can withstand temperatures as low as 4K and can resist cryogenic shock when, for instance, it is cooled from room temperature to cryogenic temperatures within a 5-10 minute window. Optically clear EP29LPSP has superior physical strength, electrical insulation, and chemical resistance properties. It also meets NASA low outgassing requirements and exhibits a low exotherm during cure. This low viscosity compound is easy to apply and bonds well to metals, glass, ceramics, and many different plastics. Curable at room temperature, EP29LPSP attains its best results when cured at 130-165°F for 6-8 hours.

In over a dozen published research articles, patents, and manufacturers' specifications, scientists and engineers have identified EP29LPSP for use in their applications due to its unparalleled performance in one or more areas. Table 1 highlights several commercial and research applications that use Master Bond EP29LPSP. Table 2 summarizes several patents that reference EP29LPSP. Following each table are brief descriptions of the role Master Bond EP29LPSP plays in each application or invention.

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