Fourier Transforms (and More) Using Light

September 30, 2021 by Al Williams 16 Comments

Linear transforms — like a Fourier transform — are a key math tool in engineering and science. A team from UCLA recently published a paper describing how they used deep learning techniques to design an all-optical solution for arbitrary linear transforms. The technique doesn’t use any conventional processing elements and, instead, relies on diffractive surfaces. They also describe a “data free” design approach that does not rely on deep learning.

There is obvious appeal to using light to compute transforms. The computation occurs at the speed of light and in a highly parallel fashion. The final system will have multiple diffractive surfaces to compute the final result.

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The Coming Copper Shortage: Aluminium Or Carbon Nanotubes To The Rescue?

September 30, 2021 by Maya Posch 90 Comments

The use of aluminium in wiring is unlikely to bring a smile to the face of anyone who has had to deal with it in a 1960s, or early 1970s-era house. The causes behind the fires and other accidents were myriad, including failure to deal with the higher thermal expansion of aluminium, the electrically insulating nature of aluminium oxide, and the general brittleness of aluminium when twisted.

Yet while copper is superior to aluminium in terms of electrical conductivity and ease of installation, copper prices have skyrocketed since the 1970s, and are on the verge of taking off to the moon. A big part of the reason is the increased use of copper in everything from electronics and electrical motors to generators, driven by large-scale deployment of wind turbines and electrical vehicles.

As the world moves to massively expand the use of electrical cars and installation of wind turbines, copper demand is predicted to outstrip current copper supply. With aluminium likely to make a big return as a result, it’s worth taking a look at modern-day aluminium-based wiring, including copper-clad aluminium and the use of carbon-based replacements. Continue reading “The Coming Copper Shortage: Aluminium Or Carbon Nanotubes To The Rescue?” →

Commonwealth Fusion’s 20 Tesla Magnet: A Bright SPARC Towards Fusion’s Future

September 27, 2021 by Maya Posch 62 Comments

After decades of nuclear fusion power being always ten years away, suddenly we are looking at a handful of endeavours striving to be the first to Q > 1, the moment when a nuclear fusion reactor will produce more power than is required to drive the fusion process in the first place. At this point the Joint European Torus (JET) reactor holds the world record with a Q of 0.67.

At the same time, a large international group is busily constructing the massive ITER tokamak test reactor in France, although it won’t begin fusion experiments until the mid-2030s. The idea is that ITER will provide the data required to construct the first DEMO reactors that might see viable commercial fusion as early as the 2040s, optimistically.

And then there’s Commonwealth Fusion Systems (CFS), a fusion energy startup. Where CFS differs is that they don’t seek to go big, but instead try to make a tokamak system that’s affordable, compact and robust. With their recent demonstration of a 20 Tesla (T) high-temperature superconducting (HTS) rare-earth barium copper oxide (ReBCO) magnet field coil, they made a big leap towards their demonstration reactor: SPARC.

A Story of Tokamaks

CFS didn’t appear out of nowhere. Their roots lie in the nuclear fusion research performed since the 1960s at MIT, when a scientist called Bruno Coppi was working on the Alcator A (Alto Campo Toro being Italian for High Field Torus) tokamak, which saw first plasma in 1972. After a brief period with a B-revision of Alcator, the Alcator C was constructed with a big power supply upgrade. Continue reading “Commonwealth Fusion’s 20 Tesla Magnet: A Bright SPARC Towards Fusion’s Future” →

3D Printed Sensor Detects Glyphosate

September 22, 2021 by Al Williams 14 Comments

Typically, detecting glyphosate — a herbicide — in a beverage requires a sophisticated test setup. But Washington State University has a 3D printed sensor that uses nanotubes to simplify the detection of the toxin.

The idea is very similar to inexpensive blood glucose monitors. The test will eventually find use for human samples, but the initial testing was for detecting contamination in orange juice.

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Astro Pi Mk II, The New Raspberry Pi Hardware Headed To The Space Station

September 22, 2021 by Tom Nardi 22 Comments

Back in 2015, European Space Agency (ESA) astronaut Tim Peake brought a pair of specially equipped Raspberry Pi computers, nicknamed Izzy and Ed, onto the International Space Station and invited students back on Earth to develop software for them as part of the Astro Pi Challenge. To date, more than 50,000 young people have had their code run on one of the single-board computers; making them arguably the most popular, and surely the most traveled, Raspberry Pis in the solar system.

While Izzy and Ed are still going strong, the ESA has decided it’s about time these veteran Raspberries finally get the retirement they’re due. Set to make the journey to the ISS in December aboard a SpaceX Cargo Dragon, the new Astro Pi MK II hardware looks quite similar to the original 2015 version at first glance. But a peek inside its 6063-grade aluminium flight case reveals plenty of new and improved gear, including a Raspberry Pi 4 Model B with 8 GB RAM.

The beefier hardware will no doubt be appreciated by students looking to push the envelope. While the majority of Python programs submitted to the Astro Pi program did little more than poll the current reading from the unit’s temperature or humidity sensors and scroll messages for the astronauts on the Astro Pi’s LED matrix, some of the more advanced projects were aimed at performing legitimate space research. From using the onboard camera to image the Earth and make weather predictions to attempting to map the planet’s magnetic field, code submitted from teams of older students will certainly benefit from the improved computational performance and expanded RAM of the newest Pi.

As with the original Astro Pi, the ESA and the Raspberry Pi Foundation have shared plenty of technical details about these space-rated Linux boxes. After all, students are expected to develop and test their code on essentially the same hardware down here on Earth before it gets beamed up to the orbiting computers. So let’s take a quick look at the new hardware inside Astro Pi MK II, and what sort of research it should enable for students in 2022 and beyond.

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Mechanisms Behind Vaccine Side-Effects: The Science That Causes That Sore Arm

September 21, 2021 by Maya Posch 85 Comments

After receiving a vaccination shot, it’s likely that we’ll feel some side-effects. These can range from merely a sore arm to swollen lymph nodes and even a fever. Which side-effects to expect depend on the exact vaccine, with each type and variant coming with its own list of common side-effects. Each person’s immune system will also react differently, which makes it hard to say exactly what one can expect after receiving the vaccination.

What we can do is look closer at the underlying mechanisms that cause these side-effects, to try and understand why they occur and how to best deal with them. Most relevant here for the initial response is the body’s innate immune system, with dendritic cells generally being among the first to come into contact with the vaccine and to present the antigen to the body’s adaptive immune system.

Key to the redness, swelling, and fever are substances produced by the body which include various cytokines as well as prostaglandin, producing the symptoms seen with inflammation and injury.

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Green Roofs Could Help Improve Solar Panel Efficiency

September 20, 2021 by Zoe Skyforest 83 Comments

There’s been a movement in architecture over the past couple of decades to help tie together large urban developments with plant life and greenery. We’ve seen a few buildings, and hundreds more renders, of tall skyscrapers and large buildings covered in vegetation.

The aesthetic is often a beautiful one, but the idea is done as much for its tangible benefits as for the sheer visual glory. Naturally, there’s the obvious boost from plants converting carbon dioxide into delicious, life-giving oxygen. However, greenery on the roofs of buildings could also help improve the output of solar installations, according to a recent study from Sydney, Australia.

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