1. Been wondering how little power a Gameboy Color or a GB Advance SP would use with completely modern manufacturing methods, like the Gameboy Color used 0.6 watts at the time which was nearly nothing (which is why it ran on TWO AA batts for hours on end) but made with a modern CPU design process it would use EVEN LESS power to the point it'd likely be an insubstantial percent of the power draw with the screen and sound being the primary power consumption but with modern high speed E-Ink displays and LED backlights it could run that down far more and a higher end speaker driver could run at a much higher efficiency albeit probably not a lot more
2. For comparison my modern smartphone runs at 0.6 watts while running things in the background, and barely 3-4 at full tilt doing file transfers to an external PC (uses almost the whole damned things resources lol)

I don't have an engineering background, so I think there is something simple I am missing with why such a concept wouldn't work, but I have had this idea for a while with the thought that it could possibly help with temperature increases caused by global warming.

The general concept is using a container material that is a good conductor of heat, holding a mechanism tied to a liquid with a high thermal expansion coefficient like methanol. Where the mechanism works by converting the negative/positive pressure differences into potential energy (via a system where expanding/contracting the containers volume will rotate different gears that convert it to potential energy, like a carjack lifting a weight) and builds up energy via day-night cycle differences in ambient temperature and possibly increasing the temperature difference by utilising (black?) paint that absorbs sunlight with a relatively good efficiency. With the idea that you could design a mechanism to utilise this built-up potential energy in a manner that produces very little heat.

With the general idea that even if this engine is not very efficient and heat is lost as both heat and other forms of energy, there should be a net reduction in the thermal energy in the environment, even if it increases nighttime temperatures.

I probably haven't explained this very well, but if you are able to design the mechanism that converts the thermal expansion of a liquid like methanol into a different form of energy, why couldn't this be used as a mechanism to passively absorb heat from hotter places?

I'm looking into potentially building a future, but I'm running into a problem. That honestly doesn't make sense. Because ICC has code charts for poured-in-place walls, whether they're forms or ICF. They also have cookie-cutter tables for frostproof footings, all of which you can get from an ICF manufacturer, but then you try to use ICF deck forms, and now you need an engineer. Defeating the whole purpose of going with ICF, which is structural strength, especially if you're trying to build one simple thing, which is a vault that has concrete on all six sides. Yet they lay it out for FEMA on how to build a 14x14 room with a concrete ceiling. But they can't do that with ICF deck forms.

How does the railroad bridge on VT-103 at about 43.4658° N, 72.8753° W work? It seems like the section on the side of the cutout would not be supported.

I found a good picture here:

https://scontent-ord5-2.xx.fbcdn.net/v/t39.30808-6/503266197_2628438010679868_3258928255850672486_n.jpg?stp=cp1_dst-webp_fr_q70&_nc_cat=104&ccb=1-7&_nc_sid=6db65e&_nc_ohc=FXfqECRpAKcQ7kNvwFrGFKZ&_nc_oc=AdqaSsWabc3H5bcz4wFuPQmCt9I-LWDeunDRpaE-9zfhQNrnGSnnIcHVGun5j9kdgFpHFNKo6ss94xsJwxoGJNLO&_nc_zt=23&_nc_ht=scontent-ord5-2.xx&_nc_gid=WsnyDyvAN69Kfdqle1m3xg&_nc_ss=7b289&oh=00_AQO-qH1q3N9xSVY5djBa66rL_vJRuVPX5sR5SVP3450E3A&oe=6AD33833

I’m putting mechanical in the flair, but I’m open to civil engineers too. :)

Amdahl's law for cache memories in computing:

Assume that:

• Hr (hit rate) is the fraction of memory accesses that can be handled by a fast but small cache memory
• Mr (miss rate) is the fraction of accesses that the cache cannot handle and have to read the larger but slow main memory
• Hr+Mr = 100%
• Tc is the cache access time
• Tm is the memory access time (also called "miss penalty")
• Tc < Tm

Then the total time to execute a program is like: T = Hr * Tc + Mr * Tm . It is often summarized as "optimize the most frequent case, and make it as frequent as possible". There are other formulations that derive from this to calculate the speedup instead of total time.

When talking about the cost of energy, in one of my previous comments, I said:

• Fr is the fraction of energy demand met by renewables (cheap but not available e.g. when there's bad weather)
• Fb is the fraction of energy demand met by a backup energy source (expensive but always available, e.g. natural gas, nuclear...)
• Fr+Fb = 100%
• Cr is the cost per kWh of renewables
• Cb is the cost per kWh of the backup source
• Cr < Cb

Then the total cost of combined energy per kWh is C = Fr * Cr + Fb * Cb

It was only after writing it that I realized the two formulas are essentially the same.

(I'm assuming the infrastructure for fossil fuel sources is already there so we only consider the cost of consumables and maintenance. Wind and solar, on the other hand, have a cost to be built and installed that is divided by the energy produced during their operational life, but there are no consumables to pay for.)

So, is this an accurate way of estimating the cost of a setup of mixed energy sources?

I was just gifted this topcon ct-80 tonometer, a machine used to check the pressure of a persons eye, but it kept giving me an error when I would attempt to use it. There’s an air check test option that I did and it gave me the code “n.g (-)” which just means no good. I’ve built computers and have delt with a lot of electrical and machanical work over the years and thought I would open it up. I found that this piston isn’t able to reach the top of the cylinder to build up air pressure. I wasn’t sure if it was just the rotary solenoid going bad or if it could be something to do with the cylinder or arm itself. Any help would be appreciated.

Wouldn't it be more conservative of materials to drain excess water with one big gate and/or pipe?

This comes from an argument I had with someone the other day. They were absolutely convinced that if you slapped 4 x 25hp electric motors in a 4wd configuration on something, 1 motor per wheel, that you'd get 100hp total out of it. Just refused to believe that it didn't scale linearly, which made the conversation I intended to have impossible.

Part of the problem was I couldn't actually explain it or demonstrate it well because I don't know how you'd actually go about calculating the actual end output from a multiple motor configuration. I could explain that you're losing energy to the more complex drive systems (depending on how you do it), and the inconsistencies between individual motors that have them working against each other, but I have no idea how to show someone on paper.

Argument is over, and I'm moved on, but it did highlight a big gap in my knowledge of the larger topic at hand, so I want to fill that in.

For slightly over half a decade, I have noted that the largest supercomputers on Earth consume orders of magnitude less power than the largest industrial facilities on Earth, and have thought that a supercomputer-at-gigawatt-scale would (obviously) be highly useful for certain types of modelling. At ~10²⁰ FLOPS₆₄ or FLOPS₃₂, these could include near-perfectly-accurate direct numerical CFD/FEA simulations of vehicles (of all types) and engines at faster-than-real-time speeds; and physically-based molecular simulations of eukaryotic cells, tissues, and simple multicellular organisms.

Even more recently, a large number of massive AI data centers have been built or are in the process of being built. My perspective is that this development is an outright existential threat to the very fabric of human civilization... but, still, finally, people are aggregating hundreds of megawatts or even gigawatts of computational horsepower into defined places!

However, these AI data centers are quite architecturally distinct from supercomputers. While like supercomputers (and unlike the data centers of the past; with their tasks including archiving social media content and running light web-based SaaS, earlier data centers were proportionally much more oriented towards storage and networking) they contain considerable arithmetic power, AI data centers are still geared for running myriads of individual agents for remote users (or, increasingly *shudders* themselves) rather than working as a whole on one or a few big tasks. As such, computational density and node interconnection are not quite as high priority as with supercomputers, as they don't have high task coherency that could be crippled by insufficient bandwidth or high latency through signal propagation delay. In other words, if, say, Colossus 2#Colossus_2_and_cluster_expansion) were to run the HPLinpack benchmark, its results would likely be very disappointing compared to the theoretical capabilities of all its constituent GPUs.

However... while current AI data centers aren't under particular pressure to be compact, the most powerful supercomputers aren't very compact either! El Capitan, the second most powerful supercomputer on Earth, takes up ~700 m²—a spherical-cow calculation indicates that a signal originating from a blade at one end of the system takes at least ~320 CPU cycles to get to the other end of the system, imposing a latency beyond the most feverous dreams of an early-2000s NetBurst engineer and already making task coherency difficult and the system less performant than it would ideally be. Crudely expanding this to a gigawatt would increase this figure to beyond 1,800 cycles... yikes. When looking at high-end supercomputers it is clear they have a large amount of "wasted" space, but it is also clear that significantly reducing that could make maintenance, power delivery, and cooling a nightmare. One might be tempted to build a gigawatt-class supercomputer in 3D in some sort of high-ceiling industrial facility to reduce signal distances, though it must be kept in mind that beneath their orderly floors lies a labyrinth of networking cables, electrical lines, and cooling water pipes; in other words, they take up more volume than might initially be apparent.

And so, the question.

Now obviously as the bolt functions currently that would make no sense as it discards the bullet casing, but perhaps if the bolt works as some sort of hand operated cooling mechanism or something? That probably wouldn’t be the most efficient way to do it, but what if it was a cheaply made home made laser rifle? Theoretically, obviously this is not realistically with current or near future technology, i’m writing a story.

At the school we are making a toy with a mechanism inspired by manual transmissions ( you can visit our simulator of the toy concept: https://grain-chain-95900853.figma.site )

However, it is proving very difficult to get those axes to align automatically without the need for a "gear shift"; we want to optimize the mechanism as much as possible since it is for a toy.

I hope you can give me some advice, ideas or references please 🙏

​

I've been building projects focused on solving practical problems in the AEC (Architecture, Engineering & Construction) industry, including:

\- BOQ Automation from PDF Drawings — automating quantity extraction and BOQ preparation from engineering drawings.

\- Tender Risk AI — exploring AI-assisted analysis of tender documents and identification of potential risks.

\- Crack Detection using Computer Vision — applying computer vision to identify cracks in structures.

\- Revit / SOQ Automation — automating the transfer of engineering quantities and data into Excel-based workflows.

\- InnovaTender — exploring AI-driven procurement and tendering, including risk analysis and blockchain-based bidding concepts.

I'm now looking to take this further by solving actual problems faced by people working in construction, infrastructure, EPC, estimation, billing, procurement, and project management.

I'd love to know: What's one repetitive or time-consuming task in your work that you wish could be automated?

It could involve Excel, drawings, BOQs, billing, tender documents, procurement, quantity reconciliation, or project reporting.

I'm interested in understanding real workflows and building practical solutions that save time and reduce manual effort — not just building AI demos.

You can explore my projects here:

GitHub: https://github.com/akarsh58

What can I do better. Always up for suggestions. Thanks.

I can join any firm if u can offer me a job too.

If you work in any of these areas, I'd love to hear your thoughts. Feel free to comment or DM me. I'd be happy to connect and explore potential collaborations!

​

I've been building projects focused on solving practical problems in the AEC (Architecture, Engineering & Construction) industry, including:

\- BOQ Automation from PDF Drawings — automating quantity extraction and BOQ preparation from engineering drawings.

\- Tender Risk AI — exploring AI-assisted analysis of tender documents and identification of potential risks.

\- Crack Detection using Computer Vision — applying computer vision to identify cracks in structures.

\- Revit / SOQ Automation — automating the transfer of engineering quantities and data into Excel-based workflows.

\- InnovaTender — exploring AI-driven procurement and tendering, including risk analysis and blockchain-based bidding concepts.

I'm now looking to take this further by solving actual problems faced by people working in construction, infrastructure, EPC, estimation, billing, procurement, and project management.

I'd love to know: What's one repetitive or time-consuming task in your work that you wish could be automated?

It could involve Excel, drawings, BOQs, billing, tender documents, procurement, quantity reconciliation, or project reporting.

I'm interested in understanding real workflows and building practical solutions that save time and reduce manual effort — not just building AI demos.

You can explore my projects here:

GitHub: https://github.com/akarsh58

What can I do better. Always up for suggestions. Thanks.

I can join any firm if u can offer me a job too.

If you work in any of these areas, I'd love to hear your thoughts. Feel free to comment or DM me. I'd be happy to connect and explore potential collaborations!

Hello! Everyone! I am the corporate events chair for the AIChE chapter at my university. The corporate team is planning a case competition for freshmen and sophomores. It will be 5 groups comprised of 4 people. There will be 2 hours allocated for research and designing a presentation and then 1 hour to present and for judges to judge. I need help coming up with a problem statement that is not super technical, as it will mostly be freshmen. I was thinking the problem statement should be so that teams can present either a process or a product. We can do something in relation to sustainability or energy or something like that. Please guys I need help!!!

Can anyone identify a source of everyday mechanical energy that is currently wasted, large enough to recover economically, and concentrated enough to collect efficiently?

ChatGPT is helping me with trying to recover lost energy from various sources for a thought experiment involving carbon footprints. I think human motion can be energy grid retrievable (piezoelectric shoes, for example, capturing walking motion) but rightfully, the ai concludes its not worth it and so if I can fortify the idea with other mechanical sources, the idea has some merit.

Ultimately, humans move around and do things like open doors, walk, push things, etc. it seems all that motion can be harnessed for the energy grid.

It just irritates me to see all that going to waste. There has to be avenues to utilize human activity to enhance the electric grid.

Or is this just sci fi talk?

We’re putting up a pop-up booth inside a department store where there are square columns that have glass cladding.

Initially, part of the agreement was they will remove the glass cladding so we can put up our own design so we designed the sides of the column with slotted wall panels with product displays which they approved.

Now, they told us we can’t remove the glass cladding and we have to find a way to put up our own cladding around the column without damaging the glass. We also can’t anchor support on their ceiling but we do have a 4 inch plywood platform placed on top of their existing flooring which we can use for support.

How can we clad the column without touching the glass if we can’t mount metal frames on the column for our cladding?

https://imgur.com/gallery/XgYbkXb

https://archive.org/details/panasonic-ct-9r10t-service-manual

I am unable to source an original cord for this tv. I have tracked down the schematics for the tv and cords. I have included an imgur link with relevant photos, including a picture of the socket and schematics.

I believe I know how it needs to be wired, but I would like input on what is the safest way to do it.

Solder the wires directly to the pins?

Ideas for insulating the pins and wire connection?

Strain relief for the pins and connection?

Any other safety concerns you see?

Any input would be much appreciated.

I have also included a link to the service manual of the tv.

For managing ambient warm temperatures or heat, such as in regions surrounding high heat output facilities which reject to the environment.

I had an idea for managing thermal energy by simply using peltier (or other thermoelectric) devices to create the necessary temperature difference necessary to drive ambient heat into a more concentrated form. This could be an underground storage system for example, some adiabatic chambers.

This underground storage system would naturally connect to a larger grid, if this idea becomes reality. Storage and transport of vapor is a project I'm currently trying to make a reality, and I am also afraid that the recent flux of new data centers is going to surprise us in a way we did not expect. So I am putting this here just in case, because I feel it may be a current viable solution which is easy to use now.

However, a more efficient version is desirable, naturally, which allows for less electric to thermal energy waste to be added. Minimizing leakage of heat then is an issue.

Hey there! I am working on a small retainer case that i expect to hand washed every now and then with soap/water. In my case i have anodised aluminium as the main case and i have rotating around a hinge point which holds the lid a rod/dowel pin and i am stuck between deciding whether to use acetal for this point or stainless steel. Stainless steel is itself corrosion resistant but i have seen that aluminium with stainless steel in wet or moisture environements is not a good combination. I expect the case to be dry most of the type anyway but occasionally it will get wet. For this i have seen acetal might be a good substitute but that comes with it's own downsides in that:

1. Much harder to source acetal dowel pins
2. Their precision/tolerances +- 0.1mm seem to be much less (relatively speaking) than stainless steel
3. They don't work as well with adhesives

The pros

1. Chemically resistant like stainless steel
2. Natural Lubrication which makes it well suited for a dowel/hinge point for rotation
3. No risk of corrosion with the aluminium part
4. On the whole cheaper (caveat this with cheaper per unit but it seems like where i am, i can only buy in packs of 1000 which means for prototyping purposes much more expensive than finding an equivalent stainless steel rod)

I think that sums up where my mind is right now between the two but please if there is anything i have got wrong then please let me know or anything i am missing.

I guess what i am hoping for is someone to make a case for using stainless steel would be fine in my case as the risk of corrosion is not too large either due to:

1. The aluminium components/tray is much larger than the rod
2. The case will be dry most of the time
3. The aluminium being anodised should help with this

But i will accept if i have to bite the bullet and go with acetal. There is also the added question of stainless steel dowel rotating around an aluminium hole frequently may damage the aluminium and acetal would not.

yes that's a dog lead i attached trying to stretch it