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lven

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Cancer Treatment on a Budget

lvenneri.com
4 points·by lven·2 năm trước·4 comments

Fourth Power Law

en.wikipedia.org
6 points·by lven·2 năm trước·0 comments

How do nuclear reactors work?

lvenneri.com
4 points·by lven·2 năm trước·0 comments

Silicon Carbide Sic Mug Using Additive Manufacturing

lvenneri.com
3 points·by lven·3 năm trước·0 comments

Additive Manufacturing of SiC and other ceramics

3dcarbide.com
23 points·by lven·3 năm trước·8 comments

Reduced Distortion Eye-Ware

lvenneri.com
5 points·by lven·3 năm trước·1 comments

comments

lven
·2 năm trước·discuss
Thanks for taking the time to think about it - very helpful comments. Will check FenBen out and stick some references in as I find them again.
lven
·2 năm trước·discuss
Do you have a better resource or recommendations? I'd be happy to remove this from the internet. I feel that most other articles on the topic would be severely self-censored because of the small amount of research and the risk you mention, or just not interested in low-cost alternative treatments without a "medical" stamp on it. Research and reporting on low-cost treatment methods is probably underfunded.
lven
·2 năm trước·discuss
Webgl + js. same approach as https://ciechanow.ski/
lven
·2 năm trước·discuss
I worked on this and host it on my site as well where it's not parceled up into bits and pieces. Have to thank Bartosz Ciechanowski. Learned a lot from his code and approach.

https://lvenneri.com/nuclear_reactor_explainer
lven
·2 năm trước·discuss
not when it's more expensive than diesel. Must find the balance.
lven
·2 năm trước·discuss
nah you can just create little holes in the sphere to illuminate the planets. negligible power loss. Earth and all the planets live on the sun's crumbs, no the (crumbs of the cumbs)^12
lven
·2 năm trước·discuss
I like the railgun analogy. I think you can stock up on other fusion cost arguments through my article, Engineering and Economic Challenges of Fusion: https://lvenneri.com/blog/ConFusion
lven
·3 năm trước·discuss
My own partisan comments on the pebble bed class of reactors (https://lvenneri.com/blog/pebble-bed-nukegumball) for those interested in a deeper yet still qualitative comparison of pebble beds and prismatic cores - the main types high temperature reactor. Long story short : pebbles offer significant disadvantages compared to prismatic geometries, summarized by this donald duck clip: https://youtu.be/shvwSBGDmE0.
lven
·3 năm trước·discuss
They will have two types of reactors. First, large centralized reactors for DD fusion to make He3. These will be more expensive and challenging because of the neutron bombardment. The other for D-He3 fusion which will be for smaller sites and produces less neutron damage.

They will make the He-3 using D-D fusion reactors (which is not aneutronic) and waiting for collected tritium to decay into He-3 (12 years). In each shot, they have to remove the he3 and T to prevent them from reacting.

In the D-he3 reactors, they cannot fully prevent the side reactions of DD and DT. But they can minimize them by controlling the mixture of he3 and D in each shot and constantly extracting the T byproduct of D-he3. Basically, they will have high ratio of he3 to D ions so that all the D ions are likely to be used in D-he3 reactions. Removing and collecting the T in each shot removes the opportunity for D-T. It will probably work to an extent, but there will still be side reactions. The overall neutronicity will likely be in the 2-5 range in the D-He3 reactors.
lven
·4 năm trước·discuss
Doesn't matter if the heat is coming from burning more fossils or nuclear fuels or intercepting more solar light - the effect on Earth's temeperature is negligible for now. You can do simple heat balance with Stefan Boltzman Law to show that the temperature of the Earth would increase by less than a tenth of a degree even if we burned 10x more fossil or nuclear fuels. The idea is that all the energy received and and generated on Earth must be reraridated at the Earth's blackbody temperature, and it only changes as the power to the 1/4th - so very small compared to the absolute temperature of the Earth ~300K, and the changes (e.g. seasons).
lven
·4 năm trước·discuss
Main problem is the rock melting temperature ~ 1500 to 2000 °C. Even the best performing nuclear fuels can only reach 1600°C in the fuel (TRISO Particle or FCM fuel) for limited periods of time, meaning 1000°C of heat delivered due to major limitations in the steels and heat transfer. They realized this early on in the Subterrene project at Los Alamos, and transitioned to electrically heated electrodes like graphite and tungsten. They even did field tests near Bandelier National Monument, digging a large diameter door sized hole using 100s of small diameter holes to form the perimeter. Even then, there are material degradation problems especially in the presence of air and water, that make rock melting pretty challenging. More recently, an MIT spinoff (Quaize or Quarkz or something like that) is using microwave emitters to vaporize the rock - which reduces material and mechanical challenges. But it's not ideal for large diameter holes - mostly for geothermal, fossil, or utility boring.

It's not clear to me that melting is less energy intensive than digging (and all it's related machinery and material movement).