#free enthalpy

[silly-hermit]

The dark magic of Thermodynamic functions

Abstract: You probably won't refer to "free enthalpy" as the "Gibbs Energy" anymore (and finally there will be sense for what an 'enthalpy' even is.)

If you stumbled upon this post by using the #thermodynamic tag on tumblr, well, please lord have mercy on you. Tho, if you truly did, he most likely had forsaken you long ago.

Internal energy 'U' and enthalpy 'H', as well as their more refined (or literally, "freer,") counterparts free energy 'F' and free enthalpy 'G', all share the same unit: energy (Joules).

Sharing the same unit implies some similitude, even between two very distinct stuff: the Eiffel tower's height is not the same as mine, but we can see how they *can* be compared.

Yet, when it gets more abstract, such as energy, the nuances aren't so clear. We're not even sure sometimes that what we define actually means anything: for what we know, it could just be a convenient way to handle the values.

What I'll tell next are analogies, not images. In analogies you can manipulate two object as being truly equivalent. Because the same rules apply for both, it's great if thinking with one of them makes it easier than with the other.

Enthalpy 'H', is to internal energy 'U', what some person's overall wealth are to their bank account.

Both 'total wealth' and 'bank account' are expressed in some currency, be it €, $, or whatever. But if we want to tell how wealthy someone is, the amount of cash on their bank account isn't enough. It could currently be at 1.000€, yet the guy in question is a CEO owning a mansion, a boat, etc. So, to get the whole wealth, we add the Value of all the Possessions (for now let's call it PV) to the bank account. If we take back our thermodynamic functions, this become:

H = U + PV

Honestly I just made the PV naming pun because I could. For coherence, I rather think it's both simpler and better to call V the "Volume (of possessions)" and P the average "Price (of possessions)." Volume analogy is straightforward. For Pressure-Price, if Price is cost per volume, then its units are €/m3, which in our analogy € act as Joules, so it also adds up.

So, an enthalpy, is a total wealth. It not only includes the core bank account (U), but also all the person's (or 'system's') belongings, via PV.

This also explain why, in chemical reactions, it's easier to talk in terms of enthalpy, and internal energy is seldom used. The same as you guess someone's wealth by looking at everything they owns rather than just their bank account (which probably you can't access anyway).

Let's get back to the thermodynamic story.

Having 1.000€ of wealth (not just bank account) mean I can afford stuff up to 1.000€ (taxes included). But if I'm being rather cautious, I would think a lot before spending my whole 1.000€, or even way less, on something. There is some kind of threshold, under which I will spontaneously spend the money, but above which I'd think twice before doing so. Out of all my wealth, I subtract some of it for savings, and the rest of the wealth is free for me to use. That's what free enthalpy (or free energy) is about.

G = H - TS

I set aside some of my wealth (-TS) to stay in a comfortable state of mind. My comfortable state of mind is an analogy for my thermodynamic equilibrium state.

Thus, if we look from the thermodynamic side of the analogy, the TS term means some kind of stored away energy. Which actually is exactly that. The TS term represents the energy the system get from how 'probable' it is. This energy cannot be retrieved in any way. So to correct a bit our analogy, rather than being about "savings", it's more like "comfort investment." You already spent this money to make your life easier, and you won't get it back. So I hope it was worth your money.

Same can go for free energy and bank account, if you only think about bank account-related purpose. (Which is why most "first principles" derivations, will use the free energy in formulas rather than the free enthalpy. They care more about the energy of the particle of the system rather than the energy of the whole system, which include the work it did at some point to occupy its volume.)

We got a grasp of what TS is, but are there analogies for T and S alone? When refining any analogy, before adding new axioms, it's better if we can let the analogy produce them itself.

TS is a product, representing some 'comfort value.' It is important to not say just 'comfort' but also precise 'value', as its units are Joules, i.e. currency € in the analogy. Very often in physics or whatever, when you have a product, you can always make the individual factors analogies of "level of something" and "the value of a level of that something." So, since TS is a comfort value, it means that either T or S is "comfort level" and the other is "the comfort value of a level." Looking at their -physical- units, K and J/K, we can infer that T is comfort level while S is comfort value of a level.

It implies that 'Kelvin' are our equivalent of 'comfort level.' Which I can kinda see how: the less comfortable it is, the more restricted we feel. And at absolute 0, total restriction, we can't move at all.

For entropy, by physical intuition we may be aware that entropy quantifies how statistically favourable a system is. Fortunately I think it's quite accurate to say that "how statistically favourable" is analogous to "how comfortable" a system is.

I like that about analogies, when you're checking the logic is self-consistent, you unveil insights simplifying the whole.

To recap:

U = Bank account

H = U + PV = Bank acc. + Possessions*price of possessions = Total wealth

G = H - TS = Total wealth - comfort level* value of comfort level = Free wealth to spend

I hope this will help you in your thermodynamic journey, but be aware that whatever path you take, they all end up in hell (Boltzmann wanted to get there faster, I guess)

[sciencesolutions]

[tenth-sentence]

Furthermore, we have shown that the sign of ∆G depends on the signs of both ∆H and ∆S and that, when ∆G = 0, there is no driving force for chemical or physical change and the system is at equilibrium.

"Chemistry" 2e - Blackman, A., Bottle, S., Schmid, S., Mocerino, M., Wille, U.

[materialsscienceandengineering]

Maxwell Relations

In the field of thermodynamics, equations derived from the definitions of thermodynamic potentials, and derivable from the symmetry of second derivatives, are known as Maxwell potentials. The four most common Maxwell relations relate the second derivatives of internal energy, enthalpy, Helmholtz free energy, and Gibbs free energy, to the derivatives involving temperature, pressure, volume, and entropy. The Maxwell relations allow scientists to substitute equivalent partial derivatives when one is more convenient than another (if, for example, one knows temperature and volume but not pressure, etc.).

Sources/Further Reading: (Image source - Wikipedia) (LibreTexts) (Blog post) (UC Irvine)

[monster-rinds]

Chapter 14: Not the key

We monsters are not lifeforms. Despite how well we can sometimes mimic life, we do not operate via the same mechanisms and drives.

I don’t remember if I’ve said this already, but as far as I know we don’t reproduce. We’re very singular beings, not made up of anything remotely like cells. We don’t have mitochondria, we have standing waves and strange attractors and things like that. We don’t have anything like DNA, and we’re essentially immortal. Except when we’re destroyed. So relationships built on sex are just not something that happens for us.

We just exist, and if we exist long enough and eat well enough, we can get pretty complicated. But when we adapt, it’s deliberate. It’s through learning. It’s through looking at the world around us and deciding what to do about it.

However, we do have one basic drive that we share with life, and that’s to eat. Like life, we are whorls of enthalpy and entropy that must continue to feed to function and exist.

And I’ve been doing that for a long, long time.

Even though I couldn’t sense the emanations of other monsters quite in the same way that Felicity could, because I was saving my energy for other things, I was still aware of our target since before Felicity had signaled me.

It was due to their behavior more than anything else.

It didn’t hurt that I was supercharged from being surrounded by a larger crowd of excited people than I’ve experienced in a long, long time. My ability to be alert and to think quickly was at what felt like my maximum.

It was exhilarating.

Anyway, before diving into the employee-only hallways and rooms of the convention center, Felicity seemed to decide that tending to her vessel’s needs was an essential part of her act. So, we went to where the food was, and she bought a bottle of water and an under-cooked slice of microwaved pizza. The corn dog vendor had already packed up.

And then we sat on a bench while she ate and drank, and I noticed our pursuer walk right on by without looking our direction, and then disappear into the crowd. No doubt they were planning on doubling back and reestablishing their bead on us from further away and in a less obvious position. 

To make that easier for them, I pulled out my phone and played with it for a while.

When Felicity was ready to move on to the next part of our plan, she squeezed my hand again.

I responded by beaming a smile and leaning in to kiss her on the neck.

She squirmed and giggled, and that made me feel like she maybe did have enough energy to do this.

The food and water was helping her host’s vessel, and that meant she had more reserves for herself, I thought.

I realized I’d been doing a lot of hoping lately, and that was a bad sign. A signal I was putting myself in too much danger. But I kept at it for the time being.

Still, I had a nasty trick up my sleeve, just in case. Well, an old and timeworn trick that I never-the-less was phenomenally good at.

---

Something that surprised and worried Felicity was that she was not seeing more emanants amongst the crowd of con-goers.

Obviously, there would be quite a number of riders and parasites amongst the humans, and just like herself, they were hard to detect unless they showed themselves. Even for her. But she expected to see more emanants like Synthia and more predators, too.

When Fuzzy-feet walked by and kept going, she expected it would be because another predator was nearby and had made a stronger claim on Synthia. But, if there was, she couldn’t spot it. And, after a bit, Fuzzy-feet appeared again, further back in the crowd, around the corner of the T-section in the hallway. She saw its aura wafting up above the masks and heads of the crowd around it.

That’s when she squeezed Synthia’s hand, while wondering what was keeping this convention so quiet and free of emanant activity.

Come to think of it, the theater had felt this way, too. Only a couple of emanants besides herself and Synthia had felt bold enough to make their presences known.

And then Synthia was leaning over and kissing her in the neck.

It was just an act, but it tickled and tingled, and playing up the natural human reaction of pleasure and embarrassment to it was easy. It came naturally, like the body knew what to do.

She giggled and squirmed, and then stood up, pulling on Synthia’s hand, whispering loudly, “Alright, let’s go fucking snog.”

Synthia squinted at her as she stood up after, saying, “Snog? What are you, 2004 LiveJournal?”

“I beg your pardon. It’s perfectly cromulent Queen’s English,” she retorted.

“What are you gonna do about it? Colonize me?” Synthia snapped, snickering.

“Maybe behind that door over there,” Felicity responded conspiratorially, pointing at a likely candidate for where they wanted to go. It was unmarked. It might just be a supply closet, but it looked heavier duty than that, like a light fire door.

The banter they’d fallen into was maybe a bit too old for their appearances, but this was an especially geeky place, and they were trying to be silly and weird to match their cover. No one seemed to even notice.

Their mark was likely too far away to hear them over the crowd anyway. It was mostly their body language that mattered here.

So, Felicity let Synthia look at the door, nod, grin, and then lead her to it. And then she stumbled along like before, but with a little more anticipatory energy.

Or so she hoped. She was still feeling fairly discombobulated from hunger and weakness, even if she had a little more lucidity than before.

Synthia paused before the door, saying, “Wait a second. I need to look something up. Maybe there’s a floor plan.” Then she pulled out her phone and keyed up the page for the con, and poked at a couple of links.

The map that she found didn’t include this door, but she left that up anyway and kept her phone out. What was more important was that she was more traceable this way.

“Yeah, let’s see where this goes,” she said. Then she reached for the nob and surreptitiously did something with the lock that neither Felicity nor Amber could do. Being a physical emanant with tight control over your form had its perks.

And what was behind the door was exactly what they were looking for, a service corridor, so they ducked in and closed it.

The color of the carpet changed from the pattern of the main floors to a solid dusty rose, and the walls were a simple textured eggshell. The ceiling had the worst fluorescent lighting installed.

It went back into the building several paces before intersecting with a main corridor that was twice as wide but with the same lack of decor.

Synthia led them to the first corner and around it, then paused, looking down at her phone but doing nothing in particular.

“Listening for our mark?” Felicity whispered as quietly as possible.

Synthia didn’t respond.

But after a couple of breaths she started moving again, looking satisfied.

“What was that about?” Felicity asked.

“You didn’t notice?” Synthia asked back.

“Notice what?”

“Perfect,” her partner in crime said. “I’ll explain later. Right now we gotta keep quiet and keep moving.”

Felicity shut up and looked back.

These corridors weren’t infinite, nor massive. There were solid double doors at either end of this big corridor. It looked like the halls existed in small sections between main areas of the convention center. But there were enough side corridors that they were able to do a little snake action.

At the next corner they took, Synthia paused again, squeezing Felicity’s hand for some reason.

They weren’t putting on their act anymore, or didn’t need to, but they were still holding hands, and Synthia was probably just subconsciously keeping it up. Maybe trying to be reassuring like a human.

Then they moved to the door at the end of that side hallway and paused yet again for a couple silent breaths, before Synthia opened it.

On the other side was an empty ballroom or meeting room of some sort. Maybe a party room. It was a little bigger than your typical classroom, but instead of a desk it had a dry bar in the corner to their right, and rails for lighting, with a wooden floor.

And it was completely devoid of any other furniture or fixtures or decor. Like it was being left a blank slate for whomever might book it in the future.

“Yes!” Synthia hissed. “Love it. Let’s set up behind the bar. They’ll have to go around to get at us.”

“Sounds good,” Felicity heard herself say, still looking around at the room. She really wasn’t as present as she wanted to be. She hoped that whatever Synthia was doing would give them a good edge.

She felt herself being dragged by the wrist into the room and toward the far wall where the entrance to the bar was. It didn’t make a lot of sense, she thought, because anyone bringing supplies from the service halls would have to make this same trek to get to the bar. But, sometimes things got rearranged for other reasons and thoughtful architecture got nullified.

And she had a fleeting thought that the bar and service door were like some sort of allegory for what was going on in her broader existence, but she couldn’t really explain how at the moment.

Then, suddenly, she felt herself falling.

“The mark is right on our tail, but moving cautiously,” she heard Synthia saying.

And then she lost consciousness.

---

I found myself looking back into the startled and confused eyes of someone I assumed was Amber.

Well, shit.

I lowered my head and loosened my hold on her hand after a quick squeeze, in case she wanted to let go. I could feel her bewilderment and alarm as it fed me.

“What…?” she asked, glancing around. “How…?” She at least appeared to recognize me when looking my way.

I tilted my head and gestured slowly downward with my left palm, “Hold on a moment, Amber. Let me catch my own bearings really quick.” But I waited to see her nod before doing my thing.

Then I did what I’d been doing in the hallways and put a little two-dimensional pseudodomain down covering the floor behind the bar.

We were in Portland, let’s call them pseudomains.

This is a thing I normally did when being pursued, if I had enough time and wherewithal to pull it off. And I wished I’d had the forethought to use it in the theater. But what we’d been doing there was so far outside my typical modus operandi it hadn’t occurred to me at the time. Here, however, the slow chase had prompted me to remember the trick.

“OK,” I said to Amber when I was done. “Let’s stand here in the middle of this space and wait. This might end up being a little scary, but you’re OK. You’ll be safe.”

“What are we doing? Why am I here with you?” she pulled herself together enough to ask.

“Have you had any blackouts before?” I asked her back.

She shook her head, “N… no? I don’t… Never.”

“What’s the last thing you remember?” I asked, keeping my words quick, to imply that she should answer quickly, too.

I could feel the other teratovore stepping on my second to last pseudomain. One more and they’d be walking in the door. There was no time to break the ice for Amber. She was just going to have to witness this if Felicity didn’t take back over real quick.

She scrunched up her face, and said, “I remember talking to you at the checkout counter with my friend Josephine. We were going to have fajitas.”

“You’ll probably remember more than that as you talk about it, or when you see Josephine next,”  I told her in a reassuring tone. “But that was yesterday.”

“Yesterday?” she gasped, radiating quite a bit of incredulity and fear. Good. I wanted her engaged but with lots of adrenaline and alertness.

“Yeah, and Josephine, I think, has a big huge crush on you,” I told her, based on my memories of Josephine’s emotions. “It’s probably reciprocal.”

“What?” she blinked, taken aback.

The last pseudomain registered a monstrous footprint. I had time for one last line and emotional reaction from her to recharge me before the door opened. I decided to see if I could trigger Felicity to come back forward again.

“Remember that monster that almost ate you?” I asked.

“What?!”

My plan was that, if Felicity wasn’t present and couldn’t attack our mark, I would expand the pseudomain beneath me to envelope the teratovore and trap them. To have the strongest control over it, I needed to be in the same domain as my attacker, so I didn’t want to do that with the one that was at the door.

What happened instead was phenomenally bad timing, to say the absolute least.

[mathematical-cheese]

Why is H the symbol for Enthalpy and F the symbol for the Helmholtz free energy?

[camuslvr]

You ever think about how the universe is already dead? Not in the poetic sense, not in some grand metaphor about human decay—literally dead. Just hasn’t finished twitching yet. See, entropy doesn’t stop. It doesn’t slow down. Everything that burns cools, everything that moves stops, and one day, every star that ever lit up the void is gonna gutter out like a cigarette in an ashtray. That’s heat death. The final silence. The end of everything.

And it’s not some distant, hypothetical horror. It’s happening right now. You feel it in your bones, in the way your body breaks down a little more every day. That ache in your joints, the way your memories slip through your fingers like sand—that’s entropy, man. That’s the same law that’s gonna tear the universe apart, working its way through you on a smaller scale. Every living thing is just a temporary structure, an arrangement of matter pretending it has permanence.

Heat death isn’t just an end. It’s the end. The final state of everything. People think of death as something with edges, something with borders—the moment your heart stops, the second the light leaves your eyes. But that’s a small death. That’s just biological failure. Heat death is bigger. More absolute. It’s not just the death of living things, or planets, or stars. It’s the death of difference.

Entropy, mathematically speaking, is a measure of disorder—more precisely, it’s the number of microstates that a system can occupy.

S = k_B ln(Ω)

Where S is entropy, k_B is Boltzmann’s constant (1.38 × 10⁻²³ joules per kelvin), and Ω is the number of possible microscopic configurations of a system. That’s the math of inevitability, right there. Because as a closed system progresses, it moves toward higher Ω, higher disorder. More ways to arrange itself. That’s why you can’t unburn a fire, why you can’t unscramble an egg—because those higher entropy states vastly outnumber the lower ones. The universe doesn’t ‘prefer’ chaos, it just follows probability. And the probability of the entire universe spontaneously reorganizing itself into something structured again? Functionally zero.

Now, extend that to a cosmic scale. The universe right now is a nonequilibrium system—it’s full of energy gradients. Hot stars, cold space. Galaxies spinning in the vast dark. But that won’t last. Every time a star burns, it’s not just producing heat and light. It’s spreading energy out, making it less usable. That’s what free energy is—energy that can still do work. Once energy spreads out evenly, once everything is the same temperature, there’s no gradient left. No work. No structure.

ΔG = ΔH - TΔS

Where G is free energy, H is enthalpy (total energy), T is temperature, and S is entropy. You see that negative sign? That’s the kicker. As entropy (S) increases, the ability to do work decreases. The universe isn’t just dying—it’s fading. Every action, every reaction, is just one more step toward equilibrium, which is just another way of saying ‘universal heat death.’

It’s not an explosion. It’s not fire or collapse. It’s just everything slowing down. Cooling. Spreading out. Until every last subatomic interaction ceases, not because something stopped it, but because there’s simply nothing left to move. No energy left to transfer. No gradients. No contrast.

And here’s the part that’ll keep you up at night: It’s irreversible. The moment the universe started, the moment that first asymmetry emerged, this was always the final destination. You can’t stop it. You can’t fight it. You can’t invent some last-minute technological miracle to turn back the thermodynamic clock. There’s no equation that undoes entropy. The only way to reset the system would be to violate the laws of physics themselves.

So when the last remnants of existence flicker out—when the black holes evaporate, when the last protons decay, when even fundamental particles stretch into meaningless diffusion—that’s it. No afterimage. No memory. Just perfect, absolute nothing.

Because everything, everything that’s ever happened, has only happened because of contrast. Hot and cold. Light and dark. Order and chaos. Without that, without imbalance, nothing can exist. No movement. No thoughts. No matter shifting from one state to another. Just a uniform, static void stretched so thin that reality itself stops functioning. You can’t even call it blackness, because blackness implies the possibility of light. You can’t even call it silence, because silence needs something to compare itself to. Heat death is worse than destruction. It’s the absence of destruction. No fire, no explosions, no final moment. Just an infinite suffocation.

No memory of what came before. No last observer to bear witness. No evidence that there was ever such a thing as ‘something.’ Just an infinite, frozen void stretching in all directions, unchanging, unbroken.

And yet, here we are. Waking up. Pouring coffee. Loving people. Building things. We pretend we matter, because the alternative is realizing we were ghosts the whole time—just flickers of heat burning themselves out in a universe that’s already gone cold.

Maybe that’s all we are. Just sparks flying off a dying flame, burning bright for a second before the darkness swallows us whole.

[solarpowerflwr]

solar power… why it’s actually really cool and you should care about it more🌞✨

ok so let me learn you a thing. we all know the sun, right? as humans, we are incredibly privileged to exist as we are in relation to the sun. as the largest body in our solar system, it gives us our wonderful water and climate cycle; light itself–which beyond being the reason we can perceive literally anything is also the reason we have plants #photosynthesis; extending beyond that, the sun is the reason we have any form of life (Planas, 2020). it’s pretty essential if i do say so myself, the fact its energy has empowered us for billions of years—and what if we could use this power for power.

as a source of energy, sunlight is incredibly immense. on average, the sun shines down 120 000 terawatts of power to the earth, which–by 2025–is 4000 times the needed amount to flow throughout the globe (Herron, 2010). however, this energy cannot be weaponized on its own. this is where solar panels come in.

these panels are composed primarily of solar cells, made from silicon #semiconductor, which captures sunlight to produce an electrical current; this process is known as the photovoltaic effect.

function of the effect:

solar cells have two layers, a negative “n-type” layer with extra electrons and a positive “p-type” layer with missing electrons or “holes.” The space where these layers are in contact, leading to the formation of an electric field, is known as a “p-n junction.” 

when sunlight hits the solar cell it transfers its energy to the electrons in the p-n junction, liberating them from their chemical bonds to conduct electricity. though, this transfer leaves behind holes, which can carry charge.

as a result of the aforementioned electric field these excited electrons and holes are induced to flow in opposite directions

this opposing flow creates an electric current 

wiring and other conductive metals in the panels collect and route this current for later use (Donev, 2024; Walker, 2024).  

another way to think of this process is that if it were a traditional chemical reaction, it would be akin to an endothermic reaction. The absorption of sunlight would necessitate a positive enthalpy gain!

though, despite the arduous set-up of this process to guarantee energy conversion, due to the nature of life, this conversion is not 100% efficient. despite common misconceptions about snow and darkness harming production, this simply isn’t the case. through storage facilities and angling of panels so snow slides off 😲–-many of these traditional problems have been circumvented (Office of Energy Efficiency & Renewable Energy, 2017).

it is instead numerous other factors limiting perfect function, such as being unable to account for all wavelengths of sunlight; the recombination of the electrical charge back to sunlight #reverse_reaction; higher temperatures messing with various properties of the panel; and sunlight simply being reflected back and not absorbing😞 (U.S. Department of Energy, n.d.). combined, this leads to an average conversion efficiency of 22% for modern solar panels. research is currently pushing this further with multi-junction and perovskite technologies (Elliott, 2024).

efficiency is not the be and end all of energy production, as “[a]n efficient solar panel is one that generates more electricity by occupying less space” (Enel X, n.d.). so, if the advantages of solar power outweigh the disadvantages of space requirements and initial costs for production, then this is virtually a non-issue.

the unique benefits of solar power make it a #game-changer🔥🔥 in energy production. its renewability, long-term cost-effectiveness, and low environmental impact show solar energy is worth investing in. solar power is more than just a sustainable energy source for underserved communities. once installed, solar panels offer free energy for decades; as long as the sun exists, so does solar power. with reliable electricity, clinics can store vaccines safely, surgeries aren’t conducted in darkness, and healthcare workers can serve remote areas more effectively. programs like UNDP’s Solar for Health have proven that solar energy doesn’t just save costs; it saves lives, empowering millions with access to essential services while lowering the health sector’s carbon footprint 👣🍃, unlike fossil fuels, solar power doesn’t emit greenhouse gases (Burton & Alers, 2019; Richardson, 2023).

circling back around to some of the negatives, as a #true comparison, while it is a bit challenging to get over the need for the significant land area as a result of the lower efficiency, innovative combined urban installations mitigate this through rooftop use (Khan & Anand, 2024). however, the other major placement for these solar farms is in the desert ecosystem. this may seem like a good use of space given the supposed bareness of these landscapes, yet in actuality, deserts are thriving fragile ecosystems, which the needed large solar installations harm (Courage, 2021). solar panels have been shown to have negative effects on wildlife, deterring common keystone species of the area from behaving and settling as they once were. this alteration in animal behaviour fundamentally changes how these ecosystems function; this change is for the worse (Chock et. al, 2020). the people living near these ecosystems are also harmed in the process as the heated climate produced from the unconverted solar energy would result in a reorganization of “global air and ocean circulation” leading to more frequent extreme weather occurrences and natural disasters in neighbouring countries, greatly impacting the health of their populations (Lu & Smith, 2021).

 the intentionality of placement matters, this does not necessarily limit the implementation of solar panels completely. instead, it promotes better land surveying and research investment to increase solar panel efficiency.

compared to a fossil fuel like coal, this needed support of solar power is minimal. coal emits on average approximately 1kg of CO₂ per kWh of energy produced, and for the amount that this CO₂ and other dangerous gases contribute to air pollution, acid rain, and respiratory diseases the efficiency for this combustion process is not that great 👎 (U.S. Energy Information Adminstration, 2023; Union of Concerned Scientists, 2017). coal plants convert 33% of energy from combustion; solar’s 22% might seem lower, but it’s infinitely cleaner and improving (Farris, 2012).

solar power isn’t just an energy source; it’s a movement toward a cleaner, healthier, and more sustainable planet. many countries are adapting its usage around the world, and it is at the forefront of the renewable energy wave (Ritchie et. al, 2024).

it reduces climate change impacts, preserving ecosystems and biodiversity; is going to be around as long as we are; and promotes personal interaction with the energy of our future. it's also really cool.

[codeshive]

Phys 362 Statistical and Thermal Physics: Homework 12 solved

1 Gibbs free energy and thermodynamic derivatives a) Starting with G = E − T S − PV, express dG in terms of dT and dP and use the result to express S and V in terms of derivatives of G (remember to indicate variables in the parentheses subscripts). b) Use the second derivative rule to show that ! ∂S ∂P ” T = − !∂V ∂T ” P . 2 Enthalpy and thermodynamic variables a) Express dH in terms of dP, dS…

[tutoroot]

What are the Basic Concepts of Chemical Thermodynamics? 

Ever wondered why a cold drink feels warm after a while? Or why does a hot cup of tea cool down? These phenomena are explained by thermodynamics, a branch of science that deals with heat and its relationship with work. In simpler terms, it’s like understanding the rules of energy exchange in the universe.  

Chemical thermodynamics focuses on the energy changes that occur during chemical reactions. Think of it as the accountant of the energy world, keeping track of how energy is spent and gained in chemical processes.  

Key concepts in chemical thermodynamics include:  

Internal energy: The total energy of a system. 

Enthalpy: The heat absorbed or released during a reaction at constant pressure.  

Entropy: A measure of disorder or randomness in a system. 

Gibbs free energy: A measure of the spontaneity of a reaction.  

Understanding the Basic Concepts of Chemical Thermodynamics  

Chemical thermodynamics is a branch of chemistry that deals with the relationship between heat and work in chemical reactions. To excel in this subject, especially for competitive exams like JEE, it’s crucial to grasp the fundamental concepts. Let’s break down some of the key terms:  

Internal Energy (U)  

Imagine a system like a container filled with tiny particles. These particles possess kinetic energy (due to their motion) and potential energy (due to their position). The internal energy is the total of all this kinetic and potential energy. It’s like the total wealth of a country, considering both cash and assets.  

Enthalpy (H): 

Enthalpy measures the heat absorbed or released during a reaction at constant pressure. Think of it as the “energy currency” of a reaction. If a reaction releases heat (exothermic), the enthalpy decreases. If it absorbs heat (endothermic), the enthalpy increases.  

Entropy (S): 

Entropy is a measure of the disorder or randomness in a system. It’s like the messiness of your room. The more scattered and disorganized the particles are, the higher the entropy. A tidy room has low entropy.  

Gibbs Free Energy (G): 

Gibbs free energy is a combination of enthalpy and entropy. It’s like a decision-maker for a reaction. If the Gibbs free energy is negative, the reaction is spontaneous and will occur on its own. If it’s positive, the reaction is non-spontaneous and requires external energy to proceed.  

Systems  

Earlier we have asked you to imagine about the “system” to have an easy understanding of the basic concepts of Thermodynamics.   

System, Surroundings, and State Functions of Thermodynamics: A Simplified Explanation  

Imagine a box filled with air. This box is our system. Everything outside the box, like the room, the people, and the weather, is the surroundings.  

Now, imagine you’re trying to understand the air inside the box. You’d want to know things like its temperature, pressure, and volume. These properties are called state functions. They only depend on the current state of the system, not on how it got there.  

Think of it like this: The state of a system is like a snapshot. It doesn’t matter how you got to that snapshot; what matters is what’s happening right now.  

Here’s a breakdown of state functions:  

Temperature: How hot or cold the air is.  

Pressure: How much force the air exerts on the walls of the box.  

Volume: How much space the air takes up.  

Every thermodynamic system in the universe can be classified into these three types:  

Open System  

Imagine you’re sipping a hot cup of tea. Have you noticed how steam escapes from the cup, and if you wait long enough, the tea cools down? This is a perfect example of an open system. In an open system, both energy (like heat) and matter (like water vapor) can move freely between the system (your tea) and the surroundings (the air around you). Just like how your body works: you eat food (matter), and your body uses it to generate energy. You also release heat and waste, constantly exchanging energy and matter with your environment.  

Closed System  

Now, think about a sealed water bottle. The water inside can’t escape because the cap prevents any matter from leaving or entering. But if you leave the bottle in the sun, the water inside will warm up. Here, only energy (heat) is being transferred through the bottle, while the water (matter) stays inside. That’s what a closed system is all about—only energy can move in or out, but it does not matter. The amount of matter remains the same, even if the temperature changes.  

Isolated System  

An isolated system is like a super-locked treasure chest that keeps everything inside, with no way for energy or matter to get in or out. Imagine a high-tech thermos that keeps your drink at the same temperature for hours. If it’s perfectly insulated, no heat escapes, and nothing gets in. That’s an isolated system. The best example? The universe itself! Nothing can come in or go out, and the total amount of energy stays constant.  

In some cases, a system can change its type. Take a car engine, for example. When fuel is injected into the engine, it’s an open system because matter (fuel) is entering. But once the fuel is inside, the engine acts as a closed system, with only energy being transferred as the engine runs.  

The Laws of Thermodynamics  

To understand thermodynamics, let’s explore its fundamental laws. There are four laws of thermodynamics, but the first three are the most relevant for our study:  

Zeroth Law of Thermodynamics: If two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other. This law helps define the concept of temperature.  

First Law of Thermodynamics (Law of Energy Conservation): Energy cannot be created or destroyed, only transferred or converted from one form to another. This law explains that the total energy of an isolated system remains constant.  

Second Law of Thermodynamics: This law introduces the concept of entropy. In simple terms, entropy measures the disorder in a system. The second law states that in any energy transfer, the total entropy of a system and its surroundings will always increase over time.  

Third Law of Thermodynamics: As the temperature approaches absolute zero, the entropy of a system approaches a constant minimum. This law implies that it’s impossible to reach absolute zero.  

Thermodynamic Equilibrium  

An essential concept in chemical thermodynamics is Thermodynamic Equilibrium. A system is in equilibrium when its macroscopic properties, like pressure, temperature, and concentration, do not change over time. For a system to reach equilibrium, the forward and reverse reactions must occur at the same rate.  

For example, consider a closed bottle of soda. Initially, when you shake it, carbon dioxide gas escapes. After some time, the rate of gas escaping equals the rate at which it dissolves back into the liquid, achieving thermodynamic equilibrium.  

Applications of Chemical Thermodynamics  

Chemical thermodynamics has wide-ranging applications across various fields. Here are some examples:  

Chemical Engineering: Thermodynamics helps engineers design reactors where energy transformations take place.  

Biochemistry: Understanding how energy is used by cells in biochemical reactions is essential for advancing medical research.  

Environmental Science: Thermodynamic principles are applied in energy conservation, understanding climate change, and predicting environmental impacts.  

These applications demonstrate the importance of chemical thermodynamics in real-world scenarios.  

Limitations of Chemical Thermodynamics  

While chemical thermodynamics is powerful, it does have limitations. For instance:  

Cannot Predict Reaction Rates: Thermodynamics can tell you if a reaction is possible, but not how fast it will occur. That’s the job of kinetics.  

Only Applies to Bulk Properties: Thermodynamics deals with macroscopic properties and does not provide detailed information about molecular-level phenomena.  

Despite these limitations, the importance of chemical thermodynamics in science and engineering remains immense.  

Conclusion 

Chemical Thermodynamics is more than just a chapter in your textbook—it’s a key to unlocking how energy behaves in chemical reactions. By understanding the laws of thermodynamics, thermodynamic equilibrium, and the applications of chemical thermodynamics, you’ll gain a deeper insight into the processes that govern the natural world.  

So, as you prepare for either your exams or any competitive exams like JEE, remember that mastering chemical thermodynamics will not only help you ace your tests but also open doors to understanding some of the most fundamental concepts in science. Keep experimenting, keep learning, and let the laws of thermodynamics guide you!  

If you’re looking for more simplified explanations like the ones above, visit the Tutoroot Blog for a wealth of learning resources. Enhance your understanding with Tutoroot’s expert Chemistry online Tuition. Ready to excel in your studies? Schedule a FREE DEMO session with Tutoroot’s online home tuition and experience personalised learning tailored to your needs. 

[precisionantibody]

Understanding Antibody Affinity Measurement: Key Principles and Techniques

The Importance of Antibody Affinity Measurement

Antibodies are proteins produced by the immune system to identify and neutralize foreign substances like pathogens. The binding strength between an antibody and its antigen is referred to as affinity. High-affinity antibodies bind more tightly to their antigens, leading to more effective neutralization. In therapeutic applications, such as monoclonal antibody development, selecting antibodies with high affinity ensures better efficacy at lower doses. For diagnostics, high-affinity antibodies improve the sensitivity and specificity of assays, leading to more accurate detection of disease markers.

Key Concepts in Antibody Affinity

Antibody affinity is governed by several factors, including the molecular interactions between the antibody's variable region and the antigen's epitope. These interactions involve hydrogen bonds, hydrophobic interactions, Van der Waals forces, and electrostatic attractions. Antibody Affinity Measurement The binding strength is typically expressed as a dissociation constant (Kd), which is the concentration at which half of the antigen-binding sites are occupied. A lower Kd value indicates a higher affinity.

Techniques for Measuring Antibody Affinity

Several methods are employed to measure antibody affinity, each with its own advantages and limitations. The most widely used techniques include surface plasmon resonance (SPR), enzyme-linked immunosorbent assay (ELISA), isothermal titration calorimetry (ITC), and biolayer interferometry (BLI).

Surface Plasmon Resonance (SPR):

SPR is a label-free, real-time technique that measures the interaction between an antibody and an antigen immobilized on a sensor chip. As the antibody binds to the antigen, changes in the refractive index near the sensor surface are detected, allowing determination of the association and dissociation rates. SPR provides a detailed kinetic analysis, making it one of the most accurate methods for affinity measurement.

Enzyme-Linked Immunosorbent Assay (ELISA):

ELISA is a widely used method in which an antigen is immobilized on a solid surface, and the antibody is added to detect binding. The strength of the interaction is determined by the amount of antibody bound, which is then quantified using an enzyme-substrate reaction that produces a color change. Although ELISA is less precise in determining kinetic rates compared to SPR, it is highly versatile and widely used in research and clinical settings.

Isothermal Titration Calorimetry (ITC):

ITC measures the heat change associated with the binding of an antibody to its antigen. By analyzing the thermodynamics of the interaction, ITC provides information on the binding constant, stoichiometry, and enthalpy. This method is particularly valuable for characterizing the energetics of binding, though it requires relatively large amounts of purified antibody and antigen.

Biolayer Interferometry (BLI):

BLI is another label-free technique that uses an optical sensor to measure changes in the thickness of a biological layer as an antibody binds to an antigen. Like SPR, BLI allows for real-time kinetic analysis, making it suitable for determining affinity with high accuracy.

Applications and Future Directions

Accurate antibody affinity measurement is critical in both research and industry. Anti Idiotype Antibodies In therapeutic antibody development, high-affinity antibodies are preferred for targeting diseases like cancer and autoimmune disorders. In diagnostics, highly specific and sensitive antibodies are essential for early disease detection. With advancements in affinity measurement techniques, researchers can better understand antibody-antigen interactions, leading to the development of more effective treatments and diagnostics.

[templesofdelight]

lets all go back to the beginning

Let's all go back to the ending

Back to basically nothing at all

Maybe that will help

Your constitution

That keeps getting sabotaged by the remnants of

Conscience

Consciously

Choosing to

Construct

These notions

for myself

Sick

Sick

Sick

too sick to work

Too privileged to go in late

Kicking the cannot down the road

Until your brain seizes control of your body and the fear causes rigor mortis that lets your stiff form finally collapse and hit the ground rigid as a

bored with the minds of the people they force you to

Sympathize with

constantly lied to that there was ever a choice to try

If I can't find another way I'm going to fucking fall apart in public don't you dare me don't you push me

Don't you dare to empathize all I want is for you

To leave it all the fuck alone

LEAVE IT THE FUCK ALONE

SOMETIMES I WISH YOU'D FADE INTO

THE BACKGROUND STATIC LIKE EVERYTHING ELSE

FADE AWAY AND LET ME FREE AND LET ME LOOSE AND LET THIS CRUMPLING DEFORMING REALITY BECOME A BILLION POINTS OF VISUAL SNOW WINKING

WEAVING OUT OF DIMENSIONALITY

Form constant. Made out of the vestiges of.

My visual acuity.

CONSTANTLY UNFAZED.GOING THROUGH A CONSTANT PHASE.NEVER ESCAPING UNTIL IT ALL.BLURS AWAY.GO AND TURN THE.SENSORY PROCESS OFF.IN THE MATRICES OF THE MIND.AND SCHEDULE IT TO START.AFTER IVE DONE WHAT I HAVE TO DO

now

Becomes then

and we'll never recapture

any of it

so stop telling me

to take time for myself

because its too selfish

To think time gives a fuck at all

What's going through its mind

Or heart

enthalpy of

empathy

so actually

MAYBE

You should

LET'S THINK FOR A SECOND

dread the moment

YOU SHOULD

time gives a fuck

at all

[mitivy]

CAS 94-34-8 High Purity N,N-（2-Cyanoethyl）-N-methyl aniline 99% /sample is free/DA 90 days

QUICK DETAILS Product Name:N,N-（2-Cyanoethyl）-N-methyl aniline CAS: 94-34-8 Molecular formula: C10H12N2 Molecular weight: 160.216 EINECS No.: 202-325-5 Other names：N-Cyanoethyl-N-methylaniline，N-Methyl-N-Cyanoethyl Aniline，N-Cyanoethyl-N-methylaniline，3-(N-Methylanilino)propionitrile，N-(2-Cyanoethyl)-N-methylaniline，3-(N-methylanilino)propanenitrile Appearance:Light yellow to brown oily liquid Purity:≥99%     Safety: Brand:MIT -IVY INDUSTRY CO.,LTD Application:Used as dye and organic pigment intermediates (such as acid red 14, basic orange 24, etc.). Port: any port in china Packing: according to the requirement Storage: Store in dry, dark and ventilated place. Transportation: by sea or by air payment methods: L/C, T/T, D/A, D/P, O/A, paypal, western union etc.accept all payment. Application N,N-dimethylaniline is a tertiary amine used in the synthesis of several triarylmethane dyes, such as peacock green. It is also used in the synthesis of magnetic Gram stains for the detection of bacteria. N, N-（2-Cyanoethyl）-N-methyl aniline CAS NO. 94-34-8 N,N-dimethylaniline, also known as N,N-dimethylaniline, dimethylaminobenzene and dimethylaniline. It is a yellow oily liquid, insoluble in water, soluble in ethanol, ether. Mainly used as dye intermediates, solvents, stabilizers, analytical reagents. Standards and Recommendations OSHA PEL: TWA 5 ppm; STEL 10 ppm (skin) ACGIH TLV: TWA 5 ppm; STEL 10 ppm (skin); Not Classifiable as a Human Carcinogen DFG MAK: 5 ppm (25 mg/m3); Confirmed Animal Carcinogen with Unknown Relevance to Humans DOT Classification:  6.1; Label: Poison Consensus Reports  Reported in EPA TSCA Inventory. Community Right-To-Know List. Specification N,N-Dimethylaniline is an organic compound with the formula C8H11N, and its systematic name is the same with the product name. With the CAS registry number 121-69-7, it is also named as N,N-Dimethylaminobenzene. It belongs to the product categories of Intermediates of Dyes and Pigments; Anilines, Aromatic Amines and Nitro Compounds; Organics; C-D, Puriss p.a. ACSNitrogen Compounds; Amines; Analytical Reagents for General Use; C8; Puriss p.a. ACS; C8 Essential Chemicals; Nitrogen Compounds; Reagent Plus; Routine Reagents; Organic Chemical. Its EINECS number is 204-493-5. In addition, the molecular weight is 121.18. Its classification codes are: (1)Human Data; (2)Mutation data; (3)Skin / Eye Irritant; (4)TSCA Flag T ; (5)Tumor data. This chemical should be sealed and stored in a cool and dry place. Moreover, it should be protected from moisture, heat and fire. This chemical is a key precursor to commercially important triarylmethane dyes such as Malachite green and Crystal violet. It serves as a promoter in the curing of polyester and vinyl ester resins. It is also used as a precursor to other organic compounds. Physical properties of N,N-Dimethylaniline are: (1)ACD/LogP: 2.135; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): 1.99; (4)ACD/LogD (pH 7.4): 2.13; (5)ACD/BCF (pH 5.5): 17.70; (6)ACD/BCF (pH 7.4): 24.59; (7)ACD/KOC (pH 5.5): 247.57; (8)ACD/KOC (pH 7.4): 343.97; (9)#H bond acceptors: 1; (10)#H bond donors: 0; (11)#Freely Rotating Bonds: 1; (12)Polar Surface Area: 3.24 Å2; (13)Index of Refraction: 1.55; (14)Molar Refractivity: 40.566 cm3; (15)Molar Volume: 127.425 cm3; (16)Polarizability: 16.082×10-24cm3; (17)Surface Tension: 34.71 dyne/cm; (18)Density: 0.951 g/cm3; (19)Flash Point: 62.778 °C; (20)Enthalpy of Vaporization: 42.974 kJ/mol; (21)Boiling Point: 193.539 °C at 760 mmHg; (22)Vapour Pressure: 0.46 mmHg at 25°C. Preparation of N,N-Dimethylaniline: N,N-Dimethylaniline can be prepared by N-benzyl-N,N-dimethyl-anilinium; bromide at the temperature of 40 °C. This reaction will need reagent NaTeH and solvent dimethylformamide with the reaction time of 4 hours. The yield is about 94%. Uses of N,N-Dimethylaniline:  N,N-Dimethylaniline can be used to produce 1-(4-dimethylamino-phenyl)-ethanone at the temperature of 50 °C. It will need reagent Yb(OTf)3 and solvent nitromethane with the reaction time of 18 hours. The yield is about 76%. Safety information of N,N-Dimethylaniline: When you are using this chemical, please be cautious about it as the following:N,N-Dimethylaniline is harmful by inhalation and in contact with skin. It is toxic by inhalation, in contact with skin and if swallowed. It has a limited evidence of a carcinogenic effect. This substance is toxic to aquatic organisms as it may cause long-term adverse effects in the aquatic environment. After contact with skin, you should wash immediately with plenty of ... (to be specified by the manufacturer). When using it, you need to wear suitable protective clothing and gloves. In case of accident or if you feel unwell, you must seek medical advice immediately (show the label where possible). It should be avoided exposure, and you need to obtain special instructions before use. You must avoid releasing it to the environment, and you need to refer to special instructions/safety data sheet. You can still convert the following datas into molecular structure: (1)SMILES: N(c1ccccc1)(C)C (2)Std. InChI: InChI=1S/C8H11N/c1-9(2)8-6-4-3-5-7-8/h3-7H,1-2H3 (3)Std. InChIKey: JLTDJTHDQAWBAV-UHFFFAOYSA-N The toxicity data of  N,N-Dimethylaniline is as follows:   Organism Test Type Route Reported Dose (Normalized Dose) Effect Source guinea pig LD50 skin > 20mL/kg (20mL/kg) SKIN AND APPENDAGES (SKIN): "DERMATITIS, OTHER: AFTER SYSTEMIC EXPOSURE" National Technical Information Service. Vol. OTS0571982, human LDLo oral 50mg/kg (50mg/kg) GASTROINTESTINAL: NAUSEA OR VOMITING GASTROINTESTINAL: OTHER CHANGES National Clearinghouse for Poison Control Centers, Bulletin. Vol. Jan/Feb, Pg. 1969, mouse LDLo oral 350mg/kg (350mg/kg)   National Toxicology Program Technical Report Series. Vol. NTP-TR-360, Pg. 1989, rabbit LD50 skin 1770uL/kg (1.77mL/kg)   American Industrial Hygiene Association Journal. Vol. 23, Pg. 95, 1962. rat LCLo inhalation 250mg/m3/4H (250mg/m3) BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY) BEHAVIORAL: EXCITEMENT Gigiena i Sanitariya. For English translation, see HYSAAV. Vol. 37(4), Pg. 35, 1972. rat LD50 oral 951mg/kg (951mg/kg) BEHAVIORAL: TREMOR BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY) LUNGS, THORAX, OR RESPIRATION: CYANOSIS National Technical Information Service. Vol. OTS0571982, rat LDLo subcutaneous 100mg/kg (100mg/kg)   "Toxicometric Parameters of Industrial Toxic Chemicals Under Single Exposure," Izmerov, N.F., et al., Moscow, Centre of International Projects, GKNT, 1982Vol. -, Pg. 55, 1982. Packaging 1kg/foil bag, 25kg/bag or drum (PV bag for inner packing, and aluminium foil bag for outer packing.) Hot sales !! China Manufacturer n,n-dimethylaniline CAS NO. 121-69-7 in Bulk Stock Name N,N-（2-Cyanoethyl）-N-methyl aniline Cas 94-34-8 Form Light yellow to brown oily liquid Other name N-Cyanoethyl-N-methylaniline，N-Methyl-N-Cyanoethyl Aniline，N-Cyanoethyl-N-methylaniline ，3-(N-Methylanilino)propionitrile，N-(2-Cyanoethyl)-N-methylaniline，3-(N-methylanilino)propanenitrile MF C10H12N2  MW 160.216  Organic Ingredient Buy Direct from China Manufacturer n,n-dimethylaniline High Purity CAS NO. 121-69-7 Shipping time by Sea (Just for reference) North America 11~30 days North Africa 20~40 days Europe 22~45 days South-east Asia 7~10 days South America 25~35 days WestAfrica 30~60 days MiddleEast 15~30 days East Asia 2~3 days Middle America 20~35 days EestAfrica 23~30 days Ocenia 15~20 days South Asia 10~25 days     Details Read the full article

[tenth-sentence]

For similar reasons, when ∆H and ∆S are both negative, ∆G will be negative (and the change spontaneous) only at low temperature:

∆G = (-ve) - (-ve) = (-ve) or (+ve)

"Chemistry" 2e - Blackman, A., Bottle, S., Schmid, S., Mocerino, M., Wille, U.

[materialsscienceandengineering]

Thermodynamic Potentials

Specific state functions that depend on so-called natural variables (such as temperature, entropy, pressure, etc.) are known as thermodynamic potentials. The set of relevant natural variables is unique for each potential, though all rely on the number of particles and potential energy. These potentials can be thought of as similar to potential energy, which is the capacity to do work:

Internal energy is the capacity to do work as well as release heat, with variables including entropy and volume

Helmholtz free energy relates to mechanical and non-mechanical work, with variables including temperature and volume

Gibbs free energy is specific to non-mechanical work, with variables including temperature and pressure

And enthalpy is the capacity to do non-mechanical work and release heat, with variables including entropy and pressure

A fifth potential is also considered common, though less well known: the grand potential.

Sources/Further Reading: (Image source - Statistical Physics) (Wikipedia) (University of Frankfurt) (Hyperphysics) (LibreTexts)

[radfestivaldreamer]

Lennox 60M10-W7212A1033 Enthalpycontrol | PartsHnC

The Lennox 60M10 W7212A1033 Enthalpy Control is an intelligent device designed to optimize comfort and efficiency in HVAC systems, particularly in furnaces and air handlers. It works by measuring the total heat content of incoming air, encompassing both temperature and humidity, which is known as enthalpy. By analyzing this data, the Enthalpy Control can determine whether using outdoor air for heating, cooling, or maintaining indoor climate is most beneficial. This allows the HVAC system to strategically leverage free outdoor air whenever possible, reducing the reliance on internal heating or cooling systems and consequently lowering energy consumption.