Engineering

Hi. Is there a replacement for typical metal HVAC ducting in CPVC, PVC, FRP, other rigid plastics, in 15cm(6") to 30cm(12") ? Something with smooth inside surface, to be insulated on its outside ? Perhaps ~1mm wall with available elbows, tees, connectors available ? -Not flexible 'hose'- What is 'schedule' 5, 10 ?

Hello everybody! You know hydrogen is thought as a way of storing energy, before transformation in a fuel cell for instance. Storing liquid hydrogen isn't very easy because it needs really cold temperatures, and pressurizing gaseous hydrogen needs heavy tanks with little capacity, so research is being done to adsorb hydrogen in a solid in the hope to store much hydrogen in a small volume under reasonable conditions. My own two-cents suggestion is to use abnormally light metallic alloys for this purpose. That is, alloys whose volume is bigger than the sum of the volumes of their constituents. My hope is, of course, that more free room is available to hydrogen in the allo…

The shank on this brush is 1/4" (6.35mm) and I want to reduce it to 6mm. Would using a 6mm die be the simplest/cheapest way or would the metal be too hard? It doesn't matter about it having a thread. I have a rotary tool that only takes 6mm bits. I've tried manually grinding one on a grinder but it was a poor job and quite off-centre. I've also tried buying 6mm bits twice but they are 1/4", despite the fact they say they are 6mm.

Hi. It has not changed much for centuries. Can there be a more ingenious, efficient way with modern technology ? The mechanical separation of heavier metals by vibration immersed in water, by a weight differential that also exists in dry process smells that could be improved. The weight differential when dry and the weight differential when submerged is there in both cases. What would be the process for evaluating efficiency ? Running the discarded material on a different process to confirm obtains additional separation ? Seems like laminar flow is important, but the fluid flow being used to carry the undesired solids destroys the laminar flow. Ho…

I previously discussed, as part of a broader thread about flood mitigation/adaptation, the notion of concave-up ellipsoids over cities to collect rainwater and prevent flooding. It was noted that they would be weak at the bottom, because of the immense pressure of all the surrounding water. On further consideration, cities are probably not the best place to put them in light of that. However, thinking about this further, I've since come up with another idea; a concave-up rain-collector (whether as ellipsoid or half-cylinder, depending on whichever is more practical) at sea, directly underneath the intertropical convergence zone. This way, rainwater…

Hello, We have developed new type of permanent magnet synchronous motor, performed a patent search and did not find anything like this. http://motresres.com/branding/toroid...rical-motoree/ May be someone saw something like that before?

I am trying to find a Node Editor GUI, preferably for python, which would allow the creation of new nodes from certain selected folders and files which already have code inside of them.

New consignee: saw no location for introductions......retired dual-discipline Engineer, Electrical-Mechanical. Have not entered any personals yet, save your time! My lifetime interests have ranged from fast cars, I.C. Engine work, High-voltage experimentation, explosives, in short, any of the things often considered "bizarre" by those outside of my little world of interest. Multi-forum member, rarely encounter many members interested in things technical. Several airline pilots present on a seniors forum presented interest, but my difficulties with an uncaring forum owner ended rather, er........ironically. I am a tinkerer, at heart.

This video showed the construction of a modestly large concave mirror using a fairly meticulous process of carefully placed reflective foil. However, I would presume that, the larger the scale on which it's conducted, the less any wrinkles in the structure matter, at least for the purposes of collecting sunlight. I'm wondering now; is there any cost-effective way to have outer space robotics (Canadarm, etc.) assemble a giant amount of reflective material in outer space? Would electrostatic repulsion and/or magnetic attraction serve to force a giant sheet of reflective material into a concave shape? Could this concave mirror then be used to melt the…

Four pistons, laser flash for thermic nitinol

For pure metal production and power

Hello dear friends! John Isaacs proposed it in the 40s for California. Peter Wadhams, Olav Orheim and Georges Mougin made studies for Saudi Arabia in the 70s and the Canarias and the UAE in 2010s. Together with Nick Sloane, they now have plans to tow icebergs from Antarctica to Australia or South Africa bbc.com Antarctica provides bigger, flatter and more sturdy sweetwater icebergs than the Arctic region do. Australia and South Africa are accessible by pushing the icebeg a bit North and letting cold oceanic currents do the rest wikimedia.org gratefully pasted here antarctica.gov.au This makes the current plans less difficult than targeting the Canarias…

Does anyone have any idea how do i make custom survival knife design and implement it? I'm taking ideas from this blog commercial url removed per rule 2.7 is it enough?

what are the present using programming language in now a days in computer science?

Problem:- I am decorating my flat with white emulsion and when I come to do the second coat it is hard to see where the first dry coat ends and the second wet coat begins. Using a bright inspection light placed at the right angle it is possible to see a slight contrast between the dry paint and the wet paint. However, this still means you have to keep moving the light source and the observation point to detect this minimal difference... I was thinking if I changed the colour of the light source and wore tinted glasses this could increase the contrast between the coats. This sounds like a physics question to me. Which colour combination would give the greate…

So Leonardo Di Caprio and Mark Ruffalo (The Hulk) both raved about this Jacobson study, but the NAS identified it was flawed and overestimated the potential for hydro storage by 100. If that's the case, no wonder I have plenty of questions about the Baldwin, Blakers and Stocks Sept 2018 which recommends pretty much the same thing: wind, water, and solar for Australia. Until recently, I used to be concerned that the energy costs of building all those pumped hydro batteries were too high based on the Weissbach EROEI study. But friends here spent some time showing me how that study is based on some really old data and the EROEI of solar PV has improved remarkably since that …

Or does a nuclear reactor require too much power for it to be miniaturized. I was told that they use miniature nuclear reactors in US submarines.

Not wire reel, not reel to reel, not eight track, not elcaset, not compact cassette. Seems indented for a pinch roller. What was this called ?

Which part of the DC circuit produces the oscillation for infra-red transmission in a remote control for television for example.

I read different stuff about it using Google and I don't know what to think cause they all have different answers saying why it would work (one person saying that Nikola Tesla intended for it to be 3 times bigger to function properly) and why it would not work . Does anyone know why it would or why it wouldn't work?

Hi, Generator of Electricity produce 1 kw per second, how much can produce of kilowatts during 1 hour ? Because online converter never give me the correct value

What kind of signals are used to control drones from long distances?

Hi. If works in a vehicle; where else is it being used to generate energy ? ----> https://www.dailymail.co.uk/sciencetech/article-2739768/The-sports-car-runs-SALTWATER-Vehicle-goes-0-60mph-2-8-seconds-just-approved-EU-roads.html

In a Sheet Metal Bender or Folder (different times/places get called different names) what maximum force is experienced and where? Not a 'press brake' that uses a die punching into the metal. But an old fashioned manually operated bender that is like a hinge laying flat. The job gets laid on top. Job gets clamped just before the intended bend line and then the 'hinge' is closed and this forces the job to bend. We are talking bending to 90 degrees. And generally making as tight a bend as possible, smallest internal radius. The purpose of the query is to enable choosing of materials to construct a viable machine. Proposed material: mild stee…

Ok so I am in South Carolina and was wanting to watch to some movies during the hurricane inside of my makeshift bunker I converted from a closet and now I am at the stage of having a bug out bag almost created, a bed, video games, board games, food and water enough for 2 weeks, a hand crack makeshift generator I made out of an old saw za, mini light bulbs I created from led's and soldered with some batteries and resistors, and a large 12 v back up battery. Was going to use cars but I am sure parents would not allow this. Right now I am trying to figure out how to convert dc to ac so that the device which is designed for ac and be able to be used. I am making a double rel…