9
submitted 1 month ago by Sal@mander.xyz to c/chemistry@mander.xyz

Abstract

Electrochemical production of fuels from solar energy, commonly referred to as solar-fuel production, is a key technology for converting abundant yet intermittent solar energy into a stable energy source. Typically, this process employs an electrolyzer coupled with photovoltaic (PV) cells through an electronic maximum power point tracking (MPPT) system. Here, we propose a chemical MPPT system, integrated directly into the electrolyzer, to enable stand-alone and unmanned liquid solar-fuel production with stabilized concentration changes from sunrise to sunset. The working principle of the MPPT system is derived from the impedance and heat-transfer properties of the electrolyzer, which incorporates a solid-state electrolyte exhibiting ionic resistivity with a negative temperature coefficient. Application of the mathematical model to a real electrolyzer energized by a commercially-available monocrystalline-Si PV panel for producing pure aqueous formic-acid solution demonstrated a high utilization factor (85%) of PV energy and a 2% external solar-to-formic-acid (eSTF) energy efficiency for 0.1 kg of formic acid from pure water and carbon dioxide (CO2) during daytime operation, all without the use of a conventional electronic MPPT system.

4
submitted 1 month ago* (last edited 1 month ago) by Sal@mander.xyz to c/abiogenesis@mander.xyz

Abstract

The origin of life (OoL) is a fundamental and long-standing scientific question. Although a variety of plausible hypotheses had been put forward, how life began on the prebiotic Earth from a pile of prehistoric inert chemicals (gases) is still a puzzle to us. Here, to unify the existing hypotheses to cover the entire scenarios, the author proposed the “nanozymes hypothesis” of the OoL on Earth, in which natural mineral nanozymes (MN-zymes) and their later upgraded organic/inorganic hybridized nanozymes played multiple key roles in the initial emergence of life molecules, especially in the manner of “inorganic photosynthesis” under primitive Earth conditions. Under the hypothesis framework, proteins, DNA, and RNA might emerged near-simultaneously, as a result of the diversity of nanozymes and catalyses, and multiple physical and chemical key roles of the MN-zymes. Besides nanozyme aspects, several fundamental and key issues on the topic are briefly discussed and several essential elements and conditions for the natural selection and survival of life molecules are proposed.

21
submitted 1 month ago by Sal@mander.xyz to c/spectroscopy@mander.xyz
21
submitted 1 month ago by Sal@mander.xyz to c/photonics@mander.xyz
11
submitted 1 month ago by Sal@mander.xyz to c/spaceweather@mander.xyz
17
submitted 1 month ago* (last edited 1 month ago) by Sal@mander.xyz to c/aboringdystopia@mander.xyz

Hello all,

This community will be removed from the instance in the near future because it is unmoderated, does not align with the instance's focus, and frequently introduces political content into the local feed, which is contrary to the instance's goal of minimizing political content.

Alternative versions of aboringdystopia are available on other instances:

!aboringdystopia@lemmy.world

!aboringdystopia@lemmy.ml

!aboringdystopia@lemm.ee

I would prefer locking the community to avoid losing visibility of the posts, but unfortunately locking a community is not an available feature.

EDIT: As Trying2KnowMyself pointed out below, it is possible to restrict the community to moderator posts. So, I have done that instead to preserve older content.

9
VIII, by Era (eramusicofficial.bandcamp.com)
submitted 1 month ago by Sal@mander.xyz to c/music@lemmy.world

Very happy and surprised to see a new release from Era!

The song 'Not You Again' is my favorite so far.

5
submitted 2 months ago by Sal@mander.xyz to c/fermentation@mander.xyz

Summary

Scientists in South Korea have discovered that a probiotic bacterium found in kimchi may help the body flush out tiny plastic particles before they can build up in organs. In lab tests, the kimchi-derived microbe clung tightly to nanoplastics even under conditions designed to mimic the human intestine, where other bacteria quickly lost their grip.

2
submitted 2 months ago by Sal@mander.xyz to c/spectroscopy@mander.xyz

Abstract

Photochemical upconversion has several potential applications in optoelectronics. However, there is yet to be demonstrated a rational approach to high efficiencies in nanoscale solid-state devices. Here we demonstrate that the liquid triplet fusion medium, 9,10-bis(n-octyl-diisopropylsilylethynyl)anthracene (NODIPS-An), which behaves as a solid on excitonic timescales, can achieve high-efficiency upconversion on the nanoscale. Owing to its amorphous structure, there are highly-coupled sites that trap upconverted states and prevent the back transfer that plagues nanoscale upconversion systems. With NODIPS-An filling the pores of a sensitized alumina nano-scaffold, we achieve an absolute photon upconversion efficiency of 8.2(4)%. The majority of efficiency losses are attributed to fluorescence and triplet energy transfer yields, and thus the self-trapping of excitons within the triplet fusion medium is demonstrated to effectively prevent the back transfer of excitons to the sensitizer. Strategies are proposed to improve the fluorescence yield and triplet energy transfer to pursue higher efficiencies in nanoscale solid-state photochemical upconversion devices.

10
submitted 2 months ago by Sal@mander.xyz to c/spectroscopy@mander.xyz

Abstract

Coumarin-based derivatives are recognized as tunable photonic building blocks due to their strong light–matter interaction and relevance for both linear and nonlinear optical applications. This work presents an investigation of the linear optical properties and multiphoton excitation response of four derivatives coupled with benzothiazole and benzimidazole moieties. The compounds 7-diethylamino-coumarin-benzothiazole, 6-bromo-coumarin-benzothiazole, and 7-diethylamino-coumarin-benzimidazole exhibit nearly identical absorption maxima (∼423–428 nm) and emission peaks (∼485 nm), while displaying pronounced differences in molar absorptivity and ground to first excited-state transition dipole moment (μ01). The 7-diethylamino-substituted derivatives show enhanced molar absorptivity (∼5.3 × 104 L mol–1 cm–1) and larger transition dipole moment (μ01 ∼ 8.1 D) compared to the bromo-substituted (μ01 ∼ 5.5 D). In contrast, 7-hydroxyl-coumarin-methyl-benzimidazole exhibits a distinct spectral signature characterized by a larger Stokes shift and lower molar absorptivity, with an intermediate μ01 ∼ 7.0 D reflecting a different electronic balance within the conjugated framework. Multiphoton excitation experiments using femtosecond laser pulses demonstrate efficient two-photon (800 nm) and three-photon (1200 nm) excited fluorescence for all derivatives. Remarkably, the hydroxylated derivative combines an exceptionally high fluorescence quantum yield (∼48%) with a measurable excited-state lifetime (∼3 ns), identifying it as the most promising candidate for bright photoluminescent probing under one-, two-, and three-photon excitation.

11
submitted 2 months ago by Sal@mander.xyz to c/neuroscience@mander.xyz
4
submitted 2 months ago by Sal@mander.xyz to c/physics@mander.xyz

Abstract

To achieve precise printing using high-viscosity paste on insulating substrates, we propose a mechanical pulling force and alternating current comodulation electrohydrodynamic (MAC-EHD) printing method. The technique effectively refines the liquid bridges of high-viscosity paste during deposition by leveraging the synergistic effect of mechanical pulling force and electric field force, thereby improving printing resolution. In addition, it achieves in situ neutralization of charge through an alternating electric field, enhancing the stability of the printing process. To address the challenge of controlling process parameters in MAC-EHD printing, we develop a high-precision prediction model for the MAC-EHD printing mode. This model determines the range of process parameters required for well MAC-EHD printing mode. Experimental results demonstrate that the flexible transparent conductive panels fabricated using this technology exhibit superior performance. These findings validate the advantages of MAC-EHD printing in terms of high resolution and high molding accuracy for high-viscosity paste deposition.

[-] Sal@mander.xyz 65 points 9 months ago

I'd rather pay for preventing the front passenger from reclining into me.

[-] Sal@mander.xyz 39 points 10 months ago* (last edited 10 months ago)

If you catch a frog in between your hands and quickly flip it around, you can get the frog into a kind of paralyzed state called 'tonic immobility'.

Here is a photo from Wikipedia:

Frog stuck in tonic immobility

OK, well, many years ago I was very interested in this phenomenon and decided to look into the literature.

I found a paper from 1928 titled "On The Mechanism of Tonic Immobility in Vertebrates" written by Hudson Hoagland (PDF link).

In this paper, the author describes contraptions he used to analyze the small movement (or lack of movement) in animals while in this state. They look kind of like torture devices:

OK, but, that's still not it.... The obscure fact is found in the first footnote of that paper, on page #2:

Tonic immobility or a state akin to it has been described in children by Pieron(1913). I have recently been able to produce the condition in adult human beings.The technique was brought to my attention by a student in physiology, Mr. W. I.Gregg, who after hearing a lecture on tonic immobility suggested that a stateproduced by the following form of manhandling which he had seen exhibited as asort of trick might be essentially the same thing. If one bends forward from thewaist through an angle of 90°, places the hands on the abdomen, and after taking adeep breath is violently thrown backwards through 180° by a man on either side,the skeletal muscles contract vigorously and a state of pronounced immobilitylasting for some seconds may result. The condition is striking and of especialinterest since this type of manipulation (sudden turning into a dorsal position) isthe most common one used for producing tonic immobility in vertebrates.

Apparently this or a similar effect can be observed in humans too?! In this paper, the author himself claims to have done this and that it works! I tried to locate more recent resources describing this phenomenon in humans but I could not find them... Is this actually possible? If so, why is this not better documented? Or, maybe it is better documented but understood as a different type of reflex today? Not sure.

[-] Sal@mander.xyz 47 points 1 year ago

Best of luck raising funds! 👍 Pinned for extra visibility.

[-] Sal@mander.xyz 43 points 1 year ago* (last edited 1 year ago)

EDIT: As indepndnt mentioned in a comment below, the OP was posted on February 14, which pre-dates the wikipedia edits. So, my conclusions below about the timeline are not valid.

Hah, sure, let's investigate 🕵️‍♂️

The term 'Chalchiuhtlicueyecatl' was added as a potential Aztec name to the English wikipedia page on February 15, 2025, by user 'Mxn'.

The description of the edit is the following:

Frum says the Aztecs had no specific name for the gulf, which is plausible in a practical sense, but Fernández gives a specific religious name and is more of a reliable source on this topic

If we investigate a bit further, we can see that the term Chalchiuhtlicueyecatl is described to be a name for the 'Gulf of Mexico' in the spanish Wikipedia: https://es.wikipedia.org/wiki/Chalchiuhtlicueyecatl

This page was updated to include the description of Chalchiuhtlicueyecatl as the 'Gulf of Mexico' in September 16, 2018. I don't have access to the citation so I don't know if the citation specifies if this term is still known/used.

If you check the history you will find that the same 'Mxn' fixed a typo in this page on February 15, 2025.

So, from this sequence of events it is highly likely that the term 'Chalchiuhtlicueyecatl' was included into the Gulf of Mexico wiki page as a result of the user Mxn performing an active search for Aztec names for the Gulf of Mexico, and finding this connection between the term an the gulf by searching on Wikipedia. This information did not come from recent news about the term being used by natives.

I can find no evidence of native people referring to the gulf of Mexico as 'Chalchiuhtlicueyecatl' more frequently or at all. I can find no mention of this becoming viral in Mexico.

I find it highly unlikely that:

  • User Mxn added an obscure Aztec term to the Wiki page two weeks ago

AND

  • This same obscure Aztec term coincidentally began being used by Mexican natives, and this trend became popular enough to be noticed by foreign media but not by Mexican media

More likely....

  • Mxn actively looked for a term and updated the English wiki
  • Someone read the English wiki, thought this would be a nice story, made the meme

And this concludes my little investigation 🧐

[-] Sal@mander.xyz 39 points 1 year ago

I find it strange that they are out-bidding each other like this when there are over 8 days left. I am not too experienced with bidding, but I thought that the normal strategy was to maybe place a placeholder bid if there is no activity, but more generally one waits until the last second to set a reasonably high bid. Going on a 1v1 with fast out-bidding over a week early seems bad for everyone except the seller. Perhaps someone can explain.

[-] Sal@mander.xyz 80 points 1 year ago

Someone needs to explain to Musk how to debug with the JSON so that the ipv6 GUI does not overflow into the git API front-end

[-] Sal@mander.xyz 50 points 2 years ago* (last edited 2 years ago)

I think that they are referring to Paxillus involotus

It is quite an interesting mushroom. It was considered "safe to eat" for a long time, but it contains an antigen that a human's immune system can learn to attack.

The antigen is still of unknown structure but it stimulates the formation of IgG antibodies in the blood serum.

I once looked into whether this immune response builds up over many exposures, or if it is a random event that has a probability of happening for each exposure. I don't remember finding a convincing answer... If it is a random event, then mushroom could be considered a "Russian roulette" mushroom that will usually provide a nice meal, but, if unlucky, you may experience the following:

Poisoning symptoms are rapid in onset, consisting initially of vomiting, diarrhea, abdominal pain, and associated decreased blood volume. Shortly after these initial symptoms appear, hemolysis develops, resulting in reduced urine output, hemoglobin in the urine or outright absence of urine formation, and anemia. Hemolysis may lead to numerous complications including acute kidney injury, shock, acute respiratory failure, and disseminated intravascular coagulation. These complications can cause significant morbidity with fatalities having been reported.

I agree with you that this is probably unrelated to the "generally similar to humans" comment. I feel like this fantasy is a combination of the above fact mixed in with the fact that the Fungi belong to the Opisthokonts, which places them closer to animals than plants, and so they share some interesting cellular characteristics with us. This places them closer to animals than plants, but "generally similar to humans" is perhaps a bit of a stretch ^_^

But, it is just a meme about a guy being hyped about mushrooms. Hopefully people don't expect memes to be super accurate 😁

[-] Sal@mander.xyz 51 points 2 years ago

Expatriate/expat

Maybe it is not a popular opinion. And perhaps calling it "bigotry" is too far. But I work in a different country from where I was born, and I consider myself an immigrant. I have however seen this trend of referring to educated professionals as "expats" to distinguish us from people who immigrate to escape conflicts and/or poverty. I don't agree that this distinction is necessary or valuable, and I feel uncomfortable when I am described with that term. If I am called that, I usually chuckle and let people know that I'm an immigrant!!

[-] Sal@mander.xyz 43 points 2 years ago* (last edited 2 years ago)
  • Password hashing occurs server-side. Even without removing the hashing step an admin can intercept the plaintext password during login. Use unique safe passwords.

  • An admin can intercept the jwt authentication cookie and use any account that lives in the instance.

  • Private messages are stored as plaintext in the database

  • Admins can see who upvotes/downvotes what

  • These are not things that are unique to Lemmy. This is common.

  • To avoid having to trust your admin, run an instance.

[-] Sal@mander.xyz 54 points 3 years ago

Really cool! I'm excited to learn more about you and the project!

What's the format? Should we submit questions beforehand, or will you process questions that arrive at the start time? I've never participated in an AMA 😅

[-] Sal@mander.xyz 48 points 3 years ago* (last edited 3 years ago)

My view is: I don't like this cultural element, and I am glad that I live in a country without it. But if I am a visitor from abroad I would not resist the local culture and try to impose my own values. If I am aware of this cultural element and I dislike it, my options would be to either avoid restaurants and other tipping situations as much as I can, or simply account for the tip when making my financial decisions, and pay it.

If I live in the country then it is different, because then I am more entitled to be a driver of change. Personally, my approach would be to support businesses with explicit no-tipping policy, and to refuse receiving tips myself.

[-] Sal@mander.xyz 56 points 3 years ago

Well, good thing that you prepared well in advance and have already built a nice alternative.

Reddit is done

view more: next ›

Sal

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