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1500 questions
4
votes
2 answers
AISC Section Modulus numbers
Why does the AISC handbook only list one figure for Section Modulus for shapes such as Angle(L) steel? Shouldn't there be two? The steel is asymmetric. Is the figure given just the Delta to the bottom or something; figuring a design only needs to…
Andyz Smith
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4
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1 answer
How to design a reinforced concrete ship keel?
I am building a small ship (or very large sailboat) that will have a concrete ballast at the base of the keel. I am looking to increase the weight of the concrete (lb/ft3), but I also want to maximize the impact resistance of the concrete to resist…
Escoce
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4
votes
3 answers
How does a frequency to voltage converter work?
I am measuring the rotational speed of a shaft using a disk with 60 cuts and an optical fork. The signal from the optical fork is sent to a frequency to voltage converter and after that to a data acquisition system.
What is the working principle of…
Razvan
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4
votes
1 answer
Principal on gaining more height based on nested poles?
How do people design height gaining based on nested poles ?
Consider this picture (I made them) :
If I want to achieve height based on these 3 poles, how they should behave?
Is this how the behave?
I had been searching over the internet I haven't…
4
votes
1 answer
Otto Cycle Efficiency
A two-stroke engine equipped with a single cylinder having a bore of 12 cm and a stroke of 50 cm operates on an Otto cycle. At the beginning of the compression stroke air is at 100 kPa, 25 ℃. The maximum temperature in the cycle is 1100 ℃ . Use the…
Chris
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4
votes
1 answer
A material to insulate a container so that water inside the container is not affected by microwaves?
I'm running an experiment and I need to have a container filled with water. The container will be placed inside a microwave oven, but I need to minimize any effect the microwaves will have on the water. How can I go about running my experiment? I'm…
Robin Alvarenga
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4
votes
1 answer
How do I cut a crack into a polymer/plastic?
We need to cut a very thin crack into a polymer plate for a research project. The closest thing to what we are looking for is Wire EDM but since the polymer we are using is not conductive we cant use that method. Any suggestions? Is there an…
Murad Nazari
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4
votes
1 answer
How does a union joint with two male threads work?
How does union joint with two male threaded ends work? Does one male end rotate 360 degrees around it axis? How is the inside of the union constructed? Can I connect two pipes with female threads using a union joint and assemble/disassemble it…
Sysrq147
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4
votes
2 answers
What diameter hole will a twist drill bit of a given size actually make in a piece of metal?
I have a piston of diameter 0.7 mm exactly and a 0.7 mm drill bit. Let's call the diameter of the piston $r_1$, the diameter of a hole at the end of a tube $r_0$, and the final-actual diameter of the tube hole $r$. Then with fluid being pushed by…
Daniel Donnelly
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4
votes
7 answers
How can I cheaply drill a 0.1 mm hole in a small piece of tungsten?
I have a 10 mm diameter rod of 99.5% pure tungsten that I want to drill a 0.1 mm hole in using my Grizzly G0768 lathe. The hole only needs to be between 0.1 mm and 1 mm deep and is for a 3D printer hot nozzle. I don't know if this will break the bit…
Daniel Donnelly
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4
votes
3 answers
Do ships powered by nuclear reactors use water for shielding?
On a different Stack, I encountered an answer that was making a comparison to nuclear powered naval ships. It was stated that the physical shielding being used was various kinds of metals. This seems... odd to me.
I assume that water is probably…
Azhdeen
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4
votes
2 answers
Accidental Torsion and Equivalent Static Load for an irregular structure
Important note: I am writing a structural FEM software from scratch, so I won't able to use existing commercial FEM package. I would need to know how all the important quantities are calculated from the first principles.
I would need to determine…
Graviton
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4
votes
1 answer
Why does my model of a wind turbine show high RPM with low power output?
I am designing a wind turbine to generate 1300 W.
I modeled the output voltage of an AC generator using the following specifics:
Number coil turns = 300.
Copper wire gauge = 1.02 mm.
Knowing the density of copper, I calculated the weight of the…
user510
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4
votes
1 answer
Deriving the deflection force equation for a beam that is fixed on both ends
I want to calculate the force-displacement equation for a beam that is fixed at both ends. I think I should use the superposition principle but I am not very sure how to get started.
I know that for, say, a beam with one fixed-end and applied load…
user5785
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4
votes
1 answer
Velocity of flue gases through a pipe
I was wondering if there is any equation that helps to calculate flue gas velocity through a pipe? Can I use the Poiseuille Equation to solve this problem by assuming the flue gas is acting as a newtonian fluid?
The pipe diameter is 3.66m, change in…
user510
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