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One of the challenges engineers face when developing technologies for use in space is that of different gravities. Mostly, engineers only have access to test beds that reflect either Earth’s normal gravity or, if they’re fortunate, the microgravity of the ISS. Designing and testing systems for the reduced, but not negligible, gravity on the Moon and Mars is much more difficult. But for some systems, it is essential. One such system is electrolysis, the process by which explorers will make oxygen for astronauts to breathe on a permanent Moon or Mars base, as well as critical ingredients like hydrogen for rocket fuel. To help steer the development of systems that will work in those conditions, a team of researchers led by computational physicist Dr. Paul Burke of the Johns Hopkins University Applied Physics Laboratory decided to turn to a favorite tool of scientists everywhere: models.

Before we explore the model, examining the problem they are trying to solve is helpful. Electrolysis immerses an electrode in a liquid and uses an electrical current and subsequent chemical reaction to split atoms apart. So, for example, if you put an electrode in water, it would separate that water into hydrogen and oxygen.

The problem comes from reduced gravity. As part of electrolysis, bubbles form on the surface of the electrode. On Earth, those bubbles typically detach and float to the surface, as the density difference between them and the remaining liquid forces them to.

Dr. Burke presented alongside other experts at the Space Resources Week Workshop back in March.
Credit – ESRIC YouTube Channel

However, in reduced gravity, the bubbles either take much longer to detach or don’t do so at all. This creates a buffer layer along the electrode’s length that decreases the electrolysis process’s efficiency, sometimes stalling it out entirely. Electrolysis isn’t the only fluidic process that has difficulty operating in reduced gravity environments – many ISS experiments also have trouble. This is partly due to a lack of complete understanding of how liquids operate in these environments – and that in itself is partly driven by a dearth of experimental data. 

Which is where the modeling comes in. Dr. Burke and his colleagues use a technique known as Computational Fluid Dynamics to attempt to mimic the forces the fluids will undergo in a reduced gravity environment while also understanding bubble formation.

Electrolysis on Earth is typically done with water, but why stop there? The team used their CFD to model two other liquids that might be used in electrolyzers – molten salt (MSE) and molten regolith (MRE). Molten salt is used on Earth, but less commonly than regular water, and has successfully produced oxygen. However, molten regolith electrolysis is still somewhat of a novel use case and has yet to be thoroughly tested. MOXIE, the experiment that famously created oxygen on Mars in 2021, used the carbon dioxide in Mars’ atmosphere and a solid-state electrode – neither representative of molten regolith.

Fraser discusses MOXIE electrolysis with Dr. Michael Hect.

Dr. Burke and his team found that, computationally, at least, MRE has the most challenging conditions in reduced gravity. It has also never been tested in any reduced gravity environment, so for now; these simulations are all engineers have to go on with if they are going to design a system.

There were a few key takeaways from the modeling, though. First, engineers should design horizontal electrodes into MRE systems, as the longer a bubble spreads across an electrode (i.e., as it goes “up” it), the longer it takes for that bubble to detach. In a horizontal configuration, the electrode has less surface area to attach to, making it more likely for the bubbles to detach and float to the surface.

Additionally, the amount of time bubbles remain attached to an electrode scales exponentially with decreasing gravity. That means bubbles on the Moon will take longer to detach than those on Mars, which will take longer than those on Earth. Consequently, electrolysis on the Moon will be less efficient than that on Mars, which will again be less efficient than that on Earth, and mission planners will need to account for these discrepancies if they plan on getting something as mission-critical as oxygen from this process. The smoothness of the electrodes also seems to matter, with rougher electrodes more likely to hold onto their bubbles and, therefore, end up less efficient.

SciShow Space explores the world of MRE.
Credit – SciShow Space YouTube Channel

Other engineering solutions can overcome all these challenges, such as a vibratory mechanism on the electrode to shake the bubbles loose. However, it’s a good idea to consider all the additional complications operations in a reduced gravity environment have before launching a mission. That’s why modeling is so important, but humanity will ultimately have to experimentally test these systems, perhaps on the Moon itself, if we plan to utilize its local resources to sustain our presence there.

Learn More:
Burke et al. – Modeling electrolysis in reduced gravity: producing oxygen from in-situ resources at the moon and beyond
UT – NASA Wants to Learn to Live Off the Land on the Moon
UT – What is ISRU, and How Will it Help Human Space Exploration?
UT – A Robotic Chemist Could Whip up the Perfect Batch of Oxygen on Mars

Lead Image:
Graphic showing the difference in bubble accumulation in low and high gravities.
Credit – Burke et al.

The post Producing Oxygen From Rock Is Harder In Lower Gravities appeared first on Universe Today.

It would be tricky to burn away the outer layers of Uranus, but doing so could reveal a possible stash of gems – in this episode of Dead Planets Society, the hosts reveal a relatively simpler technique to rob the ice giant

Efficient solar panels have helped make solar power the cheapest form of energy on the planet, and new designs based on space-age technology are going further

Why July 2024 is a prime time to see distant Pluto before it fades from view.

Lots of the ‘wow factor’ in astronomy revolves around knowing just what you’re seeing. Sure, a quasar might be a faint +14th magnitude point of light seen at the eyepiece, but it’s also a powerful energy source from the ancient Universe, billions of light-years distant.

The same case is true for finding Pluto. Though its 0.1” disc won’t resolve into anything more than a speck in even the most powerful backyard telescope, knowing just what you’re seeing is part of the thrill of finding the distant world.

Pluto in 2024

The good news is, Pluto reaches opposition for 2024 this week on July 23rd. This means it rises when the Sun sets, and is highest in the sky and well-placed for observation around midnight. 2024 sees Pluto loitering in the zodiacal constellation of Capricornus the Goat, just across the border from its former decade-long residence in Sagittarius.

A wide field finder chart for Pluto in July 2024. Credit: Stellarium

Fun fact: on a leisurely 248-year orbit, Pluto has only moved from the constellation Gemini where it was first discovered by astronomer Clyde Tombaugh in 1930, to its present position.

At the eyepiece, Pluto presents a +14th magnitude dot. You’ll have to star hop through the dense star field to locate the distant world. Sketching or photographing the region to cinch the sighting. Your watching for the slight but discernible motion of the world from one night to the next. Heavens-Above can give you the right ascension/declination search coordinates for Pluto for a given night.

The path of Pluto through late July into August. Stars are plotted down to +14th magntude. Credit: Starry Night.

I remember showing off Pluto to viewers at the Flandrau Observatory in Tucson with the 14” telescope… the world was an easy catch, even from bright downtown urban skies. Use a 6” or larger aperture telescope in your quest.

A Receding World

Pluto passed perihelion on September 5th, 1989. It is now headed out to a distant aphelion 49.3 Astronomical Units (AU or 7.4 billion kilometers) from the Sun next century in February 2114. This means that Pluto varies in brightness from an apparent magnitude of +13.7 near perihelion, to 16 times fainter at magnitude +16.3 near aphelion. Clyde was fortunate that Pluto was headed towards perihelion in the mid-20th century. Otherwise, it might well have eluded discovery (!) Pluto is getting successively fainter with each opposition in the 21st century, so the time to see it for yourself is now.

Pluto from 2016. Credit: Sharin Ahmad From a Dot to a World

Until less than a decade ago, we knew of Pluto’s brightness, distance and orbit… and not much else. One inside joke among astronomers was that Pluto’s size and mass estimates were shrinking at such a rapid rate, that by 1980 it would disappear altogether (spoiler alert: it didn’t). Charon was discovered by astronomer James Christy as a fuzzy blob peeking out from behind its parent body in images. The large moon was found using the 61-inch telescope at the Flagstaff Observatory in 1978. Since then, Hubble revealed four more moons, named Styx, Nix, Kerberos and Hydra.

At +16th magnitude, Charon should be in range of a large dedicated amateur telescope. To date, I’ve only ever seen one convincing potential capture of the large moon. Orbiting once every six days, Charon reaches a separation of about 1”… certainly, near opposition is a key time to try and carry out this extremely challenging observation. Bizarre fact: if astronauts make it to the surface of Pluto by 2107 AD, they can witness a cycle of solar eclipses, courtesy of Charon.

NASA’s New Horizons really opened up the frontier on Pluto and its moons during its historic flyby in 2015. The mission revealed the worlds in dramatic detail. Nearly a decade later, new research is still coming out on the results from the flyby. We now live in an era where we can discuss the formation of Charon, or the geology of Pluto…

New Horizons’ view of Pluto. Credit: NASA/APL/New Horizons

Good luck, on your quest to cross Pluto off of your astronomical life list.

The post Astro-Challenge: Catching Pluto at Opposition 2024 appeared first on Universe Today.

The slow-running movement, in which people meet for unhurried jogs, is booming – but don't be fooled into thinking that if there's no pain, there's no gain

Scientists utilize logic gate-based decision-making to construct circuits that control genes.

A research team has been exploring how mass layoffs and data breaches could be connected. Their theory: since layoffs create conditions where disgruntled employees face added stress or job insecurity, they are more likely to engage in risky behaviors that heighten the company's vulnerability to data breaches.

An automated assessment technique that uses artificial intelligence could revolutionize the management of Parkinson's disease.

Chemists have developed a rapid electrothermal mineralization (REM) process, which in seconds can remediate the accumulation of synthetic chemicals that can contaminate soil and the environment.

A pilot study shows that nanoscopic 3-D imaging of ancient bone not only provides further insight into the changes soft tissues undergo during fossilization, it also has potential as a fast, practical way to determine which specimens are likely candidates for ancient DNA and protein sequence preservation.

Faced with the world's impending freshwater scarcity, researchers turned to solar steam generators, which are emerging as a promising device for seawater desalination. The team sought design inspiration from trees and harnessed the potential of 3D printing. They present technology for producing efficient SSGs for desalination and introduces a novel method for printing functional nanocomposites for multi-jet fusion. Their SSGs were inspired by plant transpiration and are composed of miniature tree-shaped microstructures, forming an efficient, heat-distributing forest.

Researchers have developed a low-cost, flexible, and customizable sensor for badminton players that overcomes current monitoring constraints. The team used triboelectric sensors to construct their intelligent monitoring system because they are easy to adapt for flexible, wearable devices and to minimize interference during bending and twisting, they built a 3D-printed flexible arch-shaped sensor encased in a thermoplastic elastomer. This design is comfortable during use and can be easily customized to individual athletes.

In the crowded urban landscape, where small electric vehicles -- primarily scooters and bicycles -- have transformed short distance travel, researchers are reporting a major national surge in accidents tied to 'micromobility.'

Researchers have published new research that reports on a potential alternative and less-invasive approach to measure intracranial pressure (ICP) in patients.

Scientists use a multimodal approach that combines hard X-ray computed tomography and X-ray fluorescence imaging to see the structure and chemical processes inside of a single cell.

New research has revealed critical insights into how strategic emission cap choices can lead to cost-effective, near-100% ammonia industry decarbonization while avoiding issues such as land use constraints and grid congestion.

Researchers found that an artificial intelligence (AI) model solved medical quiz questions -- designed to test health professionals' ability to diagnose patients based on clinical images and a brief text summary -- with high accuracy. However, physician-graders found the AI model made mistakes when describing images and explaining how its decision-making led to the correct answer.

A new study shows that over half of the medicines stocked in space -- staples such as pain relievers, antibiotics, allergy medicines, and sleep aids -- would expire before astronauts could return to Earth.

A room-temperature method to decompose perfluoroalkyl substances (PFASs) using visible LED light offers a promising solution for sustainable fluorine recycling and PFAS treatment.

After several years of effort, graduate students getting paid for research or teaching at the University of Chicago joined a labor union.  Because they couldn’t form a union de novo but had to join an existing one, they became dues-paying members of the United Electrical, Radio, and Machine Workers of America, Local 11o3.  This enables graduate students who get paid as research assistants or for teaching to engage in collective bargaining and to strike against the University if the bargaining reaches an impasse. The University of Chicago opposed the students’ efforts to join a union, but the University can’t prevent it.

You can see why the University would oppose unionization, for often research assistantships and teaching are regarded by universities as training rather than jobs; and if there were a strike, it would cripple research at the school as well teaching itself, for in some courses graduate teaching assistants do much of the work. But the students prevailed.  I didn’t have much of a dog in this fight, except that I thought the possibility of strikes was a dangerous byproduct of unionizing.

But joining the union came with an unexpected downside: unions can take political and ideological positions, and as a member of one (qualified students are required to join and pay union dues), you implicitly sign on to those positions.  And you may not want to do that.  In the case at hand, the Union has taken pro-Palestinian positions, and some students, especially Jewish ones, don’t want to sign on to these positions. So a group called “Graduate Students for Academic Freedom” has sued the union, alleging that the union makes them engage in implicit endorsement of the union’s positions. That, they claim, is Constitutionally prohibited “compelled speech.” You may have already guessed that this involves the war in Gaza.

Click the screenshot to read. I’ve put an excerpt below

An excerpt by Baude (there’s more at the site):

A few years ago, the graduate students at the University of Chicago, where I teach, formed a legally recognized labor union. Last year, that union expanded to include the law school, at least to the extent that law students engage in paid work such as providing research assistance. Law students who want to work as research assistants must either join the union and pay dues, or else pay agency fees to the union even if they do not join. Either way, giving money to the union is a legally required condition of working as a research assistant.

Graduate Students United at the University of Chicago, the union, engages in political speech that some law students find quite objectionable. The union is part of the United Electrical, Radio and Mine Workers of America, which also engages in political speech. For some law students, having to give money to these causes is an unacceptable condition of employment.

Yesterday, a group of those students, Graduate Students for Academic Freedom, filed a federal lawsuit against the union arguing that the arrangement violates their First Amendment rights under cases like Janus v. AFSCME, which holds that compelled agency fees “violate[] the free speech rights of nonmembers by compelling them to subsidize private speech on matters of substantial public concern.”

You can read the complaint here, and the motion for a preliminary injunction here.

This is from the complaint, so you can see what the students are objecting to. Bolding is mine:

INTRODUCTION

1.  Graduate students at the University of Chicago have been put to the choice of halting their academic pursuits, or funding antisemitism. That is unlawful.

2.  In the Winter of 2023, graduate students at Chicago voted to unionize, and are now exclusively represented by GSU-UE—a local of United Electrical (UE).

3.  That is a real problem. Among much else, UE has a long history of antisemitism. It is an outspoken proponent of the movement to “Boycott, Divest, and Sanction” Israel (BDS)—something so clearly antisemitic that both Joe Biden and Donald Trump have condemned it as such. Indeed, for years, the union has had a consuming fixation with the world’s only Jewish state—a fixation peppered with all-too-common rhetoric. UE has charged Israel with “occupying” Palestine; has branded Israel an “apartheid regime”; and has accused Israel of committing “ethnic cleansing.”

4.  GSU-UE is cut from the same cloth. On campus, it has not only echoed its parent union’s rhetoric, but has added to it. It took pains to publicly “reaffirm” its commitment to BDS just one week after the October 7 terrorist attacks. And it has joined the “UChicago United for Palestine Coalition,” which gained notoriety for its protest encampment and hostile takeover of the Institute of Politics. Through it, GSU-UE has joined calls to “honor the martyrs”; fight against campus “Zionists”; resist “pigs” (i.e., police); “liberate” Palestine from the “River to the Sea,” and by “any means necessary”; and “bring the intifada home.” Jimmy Hoffa’s union this is not.

5.  Nonetheless, under a recent collective bargaining agreement extracted by the GSU-UE, graduate students at the University must now either become dues-paying members of the union, or pay it an equivalent “agency fee,” as a condition of continuing their work as teaching assistants, research assistants, or similar positions.

6.  Constitutionally speaking, that is not kosher. The union’s ability to obtain agency fees from nonconsenting students is the direct product of federal law—i.e., it involves governmental action, subject to the First Amendment. But if GSU-UE wishes to wield such federally backed power, it must accept the responsibility that comes with it; it cannot use a government-backed cudgel, outside constitutional constraint. And if the First Amendment means anything, it means students cannot be compelled to fund a group they find abhorrent as the price of continuing their work.

7.  The stories of Plaintiff’s members lay bare the stakes that are at issue here. One member is an Israeli; another a proud Jew with family fighting in Israel; and some are graduate students simply horrified by the union’s antisemitism—as well as its other (to put it mildly) controversial political positions, which reach well beyond collective bargaining to virtually every hot-button subject (e.g., abortion, affirmative action, policing, gender ideology, even the judiciary). Although members come from different backgrounds, none can stomach sending a penny to this union.

Now I’m no lawyer (I only play one on television), but it seems that this is indeed compelled speech: Jewish students are being forced to endorse policies that can be regarded as anti-Israel and likely as antisemitic. Nor do I know the solution, unless it’s to ditch the agreement that qualified students should have to join the union.  It seems to me, in my ignorance, that unions, like universities, should be “institutionally neutral”: they should not take political or ideological positions that have nothing to do with the working of the union itself.

The First Amendment itself prohibits compelled speech. As a free-speech site says,

The compelled speech doctrine sets out the principle that the government cannot force an individual or group to support certain expression. Thus, the First Amendment not only limits the government from punishing a person for his speech, it also prevents the government from punishing a person for refusing to articulate, advocate, or adhere to the government’s approved messages.

The Supreme Court’s decision in West Virginia State Board of Education v. Barnette (1943) is the classic example of the compelled speech doctrine at work.

In this case, the Court ruled that a state cannot force children to stand, salute the flag, and recite the Pledge of Allegiance. The justices held that school children who are Jehovah’s Witnesses, for religious reasons, had a First Amendment right not to recite the Pledge of Allegiance or salute the U.S. flag.

In oft-cited language, Justice Robert H. Jackson asserted, “If there is any fixed star in our constitutional constellation, it is that no official, high or petty, can prescribe what shall be orthodox in politics, nationalism, religion, or other matters of opinion or force citizens to confess by word or act their faith therein.”

The problem, of course, is that this doctrine applies only to the government punishing people for their speech or for refusing to adhere to approved governmental speech. Since schools are arms of the government, they can’t be forced, as noted above, to salute the flag or recite the Pledge of Allegiance.  But the plaintiffs argue that the power of unions ultimately derives from the government—from legislative acts. From the complaint:

80. Step one asks: “Whether the claimed constitutional deprivation resulted from the exercise of a right or privilege having its source in state authority.” Edmonson v. Leesville Concrete Co., 500 U.S. 614, 620 (1991). And the answer here is yes: GSU-UE’s extraction of fees is the product of its legal power to bind all workers to a single collective bargaining agreement, as their sole and exclusive representative.

81. The Supreme Court has said as much: The “collection of fees from nonmembers is authorized by an act of legislative grace—one that we have termed ‘unusual’ and ‘extraordinary.’” Knox v. SEIU, Local 1000, 567 U.S. 298, 313-14 (2012).

This case, then, would seem to be an important one, for it could decide whether unions in general can indeed take political positions that are seen as implicitly endorsed by their members.  And, of course, unions regularly endorse political candidates.

The fate of this case thus depends on whether the compelled speech involved in being a union member is construed as being connected with government. As I said, I think unions, representing a broad spectrum of views among their members, should be politically neutral even if there’s no governmental connection. Compelled speech is chilled speech and inhibits free speech; this is why our university has its institutional neutrality embodied in the Kalven report.

But if the court does find that union activities occur under the aegis of government, then it’s game over: the plaintiffs win. We shall see.