A device within a vertical rectangular frame is shown, with a control box on the front and an LCD display. Within the frame, a grid of syringes is seen held upright beneath two parallel plates.

Building A Multi-Channel Pipette For Parallel Experimentation

One major reason for the high cost of developing new drugs and other chemicals is the sheer number of experiments involved; designing a single new drug can require synthesizing and testing hundreds or thousands of chemicals, and a promising compound will go through many stages of testing. At this scale, simply performing sequential experiments is wasteful, and it’s better to run tens or hundreds of experiments in parallel. A multi-channel pipette makes this significantly simpler by collecting and dispensing liquid into many vessels at once, but they’re, unfortunately, expensive. [Triggy], however, wanted to run his own experiments, so he built his own 96-channel multi-pipette for a fiftieth of the professional price.

The dispensing mechanism is built around an eight-by-twelve grid of syringes, which are held in place by one plate and have their plungers mounted to another plate, which is actuated by four stepper motors. The whole syringe mechanism needed to move vertically to let a multi-well plate be placed under the tips, so the lower plate is mounted to a set of parallel levers and gears. When [Triggy] manually lifts the lever, it raises the syringes and lets him insert or remove the multi-well. An aluminium extrusion frame encloses the entire mechanism, and some heat-shrink tubing lets pipette tips fit on the syringes.

[Triggy] had no particularly good way to test the multi-pipette’s accuracy, but the tests he could run indicated no problems. As a demonstration, he 3D-printed two plates with parallel channels, then filled the channels with different concentrations of watercolors. When the multi-pipette picked up water from each channel plate and combined them in the multi-well, it produced a smooth color gradient between the different wells. Similarly, the multi-pipette could let someone test 96 small variations on a single experiment at once. [Triggy]’s final cost was about $300, compared to $18,000 for a professional machine, though it’s worth considering the other reason medical development is expensive: precision and certifications. This machine was designed for home experiments and would require extensive testing before relying on it for anything critical.

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Improving The Cloud Chamber

Want to visualize radioactive particles? You don’t need a boatload of lab equipment. Just a cloud chamber. And [Curious Scientist] is showing off an improved miniature cloud chamber that is easy to replicate using a 3D printer and common components.

The build uses a Peltier module, a CPU cooler, an aluminum plate, thermal paste, and headlight film. The high voltage comes from a sacrificed mosquito swatter. The power input for the whole system is any 12V supply.

The cloud chamber was high tech back in 1911 when physicist Charles T. R. Wilson made ionizing radiation visible by creating trails of tiny liquid droplets in a supersaturated vapor of alcohol or water. Charged particles pass through, leaving visible condensation trails.

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Neutrino Transmutation Observed For The First Time

Once upon a time, transmutation of the elements was a really big deal. Alchemists drove their patrons near to bankruptcy chasing the philosopher’s stone to no avail, but at least we got chemistry out of it. Nowadays, anyone with a neutron source can do some spicy transmutation. Or, if you happen to have a twelve meter sphere of liquid scintillator two kilometers underground, you can just wait a few years and let neutrinos do it for you. That’s what apparently happened at SNO+, the experiment formally known as Sudbury Neutrino Observatory, as announced recently.

The scinillator already lights up when struck by neutrinos, much as the heavy water in the original SNO experiment did. It will also light up, with a different energy peak, if a nitrogen-13 atom happens to decay. Except there’s no nitrogen-13 in that tank — it has a half life of about 10 minutes. So whenever a the characteristic scintillation of a neutrino event is followed shortly by a N-13 decay flash, the logical conclusion is that some of the carbon-13 in the liquid scintillator has been transmuted to that particular isotope of nitrogen.

That’s not unexpected; it’s an interaction that’s accounted for in the models. We’ve just never seen it before, because, well. Neutrinos. They’re called “ghost particles” for a reason. Their interaction cross-section is absurdly low, so they are able to pass through matter completely unimpeded most of the time. That’s why the SNO was built 2 KM underground in Sudbury’s Creighton Mine: the neutrinos could reach it, but very few cosmic rays and no surface-level radiation can.  “Most of the time” is key here, though: with enough liquid scintillator — SNO+ has 780 tonnes of the stuff — eventually you’re bound to have some collisions.

Capturing this interaction was made even more difficult considering that it requires C-13, not the regular C-12 that the vast majority of the carbon in the scintillator fluid is made of. The abundance of carbon-13 is about 1%, which should hold for the stuff in SNO+ as well since no effort was made to enrich the detector. It’s no wonder that this discovery has taken a few years since SNO+ started in 2022 to gain statistical significance.

The full paper is on ArXiv, if you care to take a gander. We’ve reported on SNO+ before, like when they used pure water to detect reactor neutrinos while they were waiting for the scintillator to be ready. As impressive as it may be, it’s worth noting that SNO is no longer the largest neutrino detector of its kind.

Molecular beam epitaxy system Veeco Gen II at the FZU – Institute of Physics of the Czech Academy of Sciences. The system is designed for growth of monocrystalline semiconductors, semiconducting heterostructures, materials for spintronics and other compound material systems containing Al, Ga, As, P, Mn, Cu, Si and C.

Germanium Semiconductor Made Superconductor By Gallium Doping

Over on ScienceDaily we learn that an international team of scientists have turned a common semiconductor germanium into a superconductor.

Researchers have been able to make the semiconductor germanium superconductive for the first time by incorporating gallium into its crystal lattice through the process of molecular-beam epitaxy (MBE). MBE is the same process which is used in the manufacture of semiconductor devices such as diodes and MOSFETs and it involves carefully growing crystal lattice in layers atop a substrate.

When the germanium is doped with gallium the crystalline structure, though weakened, is preserved. This allows for the structure to become superconducting when its temperature is reduced to 3.5 Kelvin. Read all about it in the team’s paper here (PDF).

It is of course wonderful that our material science capabilities continue to advance, but the breakthrough we’re really looking forward to is room-temperature superconductors, and we’re not there yet. If you’re interested in progress in superconductors you might like to read about Floquet Majorana Fermions which we covered earlier this year.

The Lethal Danger Of Combining Welding And Brake Cleaner

With the availability of increasingly cheaper equipment, welding has become far more accessible these days. While this is definitely a plus, it also comes with the elephant-sized asterisk that as with any tool you absolutely must take into account basic safety precautions for yourself and others. This extends to the way you prepare metal for welding, with [Dr. Bernard], AKA [ChubbyEmu] recently joining forces with [styropyro] to highlight the risks of cleaning metal with brake cleaner prior to welding.

Much like with common household chemicals used for cleaning, such as bleach and ammonia, improper use of these can produce e.g. chlorine gas, which while harmful is generally not lethal. Things get much more serious with brake cleaner, containing tetrachloroethylene. As explained in the video, getting brake cleaner on a rusty part to clean it and then exposing it to the intensive energies of the welding process suffices to create phosgene.

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Memory At The Speed Of Light

Look inside a science fiction computer, and you’ll probably see tubes and cubes that emit light. Of course, it’s for effect, but the truth is, people do think light computing may be the final frontier of classical computing power. Engineers at the University of Southern California Information Sciences Institute and the University of Wisconsin-Madison are showing off a workable photonic latch — a memory element that uses light.

The device uses a commercial process (GlobalFoundries (GF) Fotonix Silicon Photonics platform) and, like a DRAM, regenerates periodically to prevent loss of the memory contents.

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Thorium-Metal Alloys And Radioactive Jet Engines

Although metal alloys is not among the most exciting topics for most people, the moment you add the word ‘radioactive’, it does tend to get their attention. So too with the once fairly common Mag-Thor alloys that combine magnesium with thorium, along with other elements, including zinc and aluminium. Its primary use is in aerospace engineering, as these alloys provide useful properties such as heat resistance, high strength and creep resistance that are very welcome in e.g. jet engines.

Most commonly found in the thorium-232 isotope form, there are no stable forms of this element. That said, Th-232 has a half-life of about 14 billion years, making it only very weakly radioactive. Like uranium-238 and uranium-235 it has the unique property of not having stable isotopes and yet still being abundantly around since the formation of the Earth. Thorium is about three times as abundant as uranium and thus rather hard to avoid contact with.

This raises the question of whether thorium alloys are such a big deal, and whether they justify removing something like historical artefacts from museums due to radiation risks, as has happened on a few occasions.

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