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1500 questions
6
votes
2 answers
System identification on a system with constraints
I am trying to estimate a transfer function for a pan - tilt unit which is not as easy as I hoped.
Its input parameter is a velocity, but it is constrained to move from 0° - 359° and the other way around. Saying in another way, it is not capable of…
bob
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6
votes
1 answer
Identify this bomb disposal equipment
A recent news item featured this photo of a WW2 bomb being prepared for detonation.
Can anyone identify the purpose of the large widget sitting on the bomb? it's got a lot of cooling fins on it, and there appears to be fan on the right hand side.…
ConanTheGerbil
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6
votes
4 answers
Determining pressures of a compressible gas
A friend and I wrote a paper for a fluids class discussing the details (as they relate to fluid dynamics) of constructing a cannon that could shoot a steak fast enough to cook it.
We quickly discovered (but not quickly enough to change our topic)…
cKrug
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6
votes
3 answers
What is the difference between fault tolerance and robustness of a system?
I am trying to understand the difference in the definition of "fault tolerance" and "robustness" when it comes to system design.
For instance, what would be the main design considerations or what would be the definition of the terms when looking at…
WalyKu
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6
votes
2 answers
How to equalise the water distribution in a leaky pipe irrigation system?
I have a 200 litre water butt and plenty of 22 mm plumbing pipe and fittings and I want to build an irrigation system for my vegetable patch so that I can open the tap after a few dry days and ensure all my plants get equal amounts of water from the…
jhabbott
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6
votes
1 answer
Is there a standard percentage to increase structural steel weight to account for bolts?
Weight of Structural Steel
When calculating the weight of a steel structure, I usually calculate the weight of all of the various members and plates first. I then add an additional percentage to account for the weight of nuts and bolts. This…
hazzey
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6
votes
2 answers
Pipe seized to inaccessible coupling - how to attach a new pipe?
A friend of mine that doesn't use the internet much runs a commercial laundry. They use an old 'Manlove Tullis' laundry calendar (c. 1980) that looks like this:
(click to enlarge photos)
Essentially, it is a machine with 3 rollers (2 visible in…
Danny Beckett
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6
votes
2 answers
How to design a narrow bearing that supports shear direction load
I need to connect two flat bars of metal with some kind of bearing that doesn't increase the joint thickness by more than 2-3mm (the less the better), as shown here:
There are almost no axial loads but the peak lateral (shearing) stress on the…
SF.
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6
votes
3 answers
Do references for the California PE application have to be California PE's?
Here is the link to the current CA PE Exam application:
http://www.bpelsg.ca.gov/pubs/forms/ceapp.pdf
Page 2, which is the list of engagements/references, states:
For each engagement claimed as qualifying experience, list the name of the person…
Rick
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6
votes
3 answers
Is a distributed load in two parts equal to a full distributed load?
I have a structure like such:
Due to my lack of knowledge of ANSYS, I have made the singular distributed loading (GI) represented as two distributed loadings (GH and HI).
Would this be an accurate model?
I feel like there should be some bending in…
General Stubbs
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6
votes
3 answers
How are dangerous to build things studied?
How are dangerous to build things studied?
Such as, nuclear reactors, jet engines, sawing machines.
How do engineers discover, how they ought to be built, while avoiding getting or getting others hurt?
Is there perhaps a component of "anticipating…
mavavilj
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6
votes
2 answers
Summary of major outage management works needed in the 4th decade of a nuclear reactor?
I've noticed that quite a few commercial nuclear reactors have an extended outage (they close down for several months) some time late in their third decade, and the maintenance works during the closure involve significant investment. This cost has…
410 gone
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6
votes
2 answers
How to avoid dyed liquids staining reflective/transparent surfaces
I'm dealing with some hydrocarbons (diesel, gas oil, kerosene, ethanol) where I'm putting them in a chamber and shining light through them to hit a sensor on the other side in order to measure their colour. Unfortunately what I'm finding is that the…
Amr Bekhit
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6
votes
4 answers
What are the technical obstacles for using flywheel-based regenerative braking on bicycles?
Is it possible to convert the energy you would normally lose when braking your bicycle to rotational energy by attaching an extra wheel which would start to rotate once you use your brakes? E.g., when facing a red light after riding down a hill.
If…
Gert
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6
votes
2 answers
Are electronic cigarette "atomizers" just evaporating the fluid?
Electronic cigarette elements that heat the fluid are usually termed "atomizers." They are usually just some nichrome wire or similar wrapped around a wick that becomes saturated with the nicotine fluid.
What is the process that "vaporizes" the…
Jodes
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