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How can I block ultrasound from an automotive transducer at about 8'?
We are testing a new ultrasound product using a Texas Instruments PGA450 automotive transducer.
Three of us are sharing a lab and we need some kind of ultrasound-blocking partition walls around each product to prevent interference. Think cubicle…
Doug Null
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Calculating torque needed to climb a graded hill
I've been designing an electric skateboard which is driven by only one of the rear wheels (for the moment). As I was picking out motors for the board, I soon realized I would need to find a balance between torque needed to climb hills, and RPM to…
Satchel
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What is the mathematical derivation for shear center of a beam?
For me, it's a bit hard to imagine where shear center can be, and what purpose it serves. The definition I found online is very vague:
Shear center is defined as the point on the beam section where load is
applied and no twisting is…
Graviton
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1 answer
How is fuel mixed with air in a jet engine?
I am working on an idea that involves a jet engine, but I don't quite know how the fuel system works. In a combustion engine like that in a car, you have nozzles that spray the fuel into the piston chambers (I think, correct me if I am mistaken),…
cluemein
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How can I filter out a signal while extracting only the desired one?
I know that my input signal contains a main sinusoidal signal, and I know its frequency but not its amplitude.
Until now, I have been successfully using the least-squares method to generate a sinusoidal signal with the least difference from my…
chouaib
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6
votes
2 answers
Is it a problem to have two heat sources controlled for different temperatures on the same heating circuit?
This is the situation - I have three heat sources, called CHP, burner 1 and burner 2 on the same circuit. All three feed to the same heating manifold, with various heat demands.
Preferably I want to heat with the CHP; if that is not sufficient,…
mart
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Schaeffler, De Long, and WRC welding diagrams - which steels can be used?
I am working on a simple program that would help welder to count how much ferrite, austenite etc. there is in weld. I am focusing on stainless steel.
I have decided to use 3 graphs: Schaeffler, De Long and WRC. What I don't know is for which…
bartosz.baczek
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3 answers
How are loads transferred to bearing piles in a wall pier?
I've been working on the design of a reinforced concrete wall pier for a three-span bridge. I roughed out the design based on a number of example plan sets and now that I'm taking a crack at the actual design calculations, I'm questioning the logic…
CableStay
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3 answers
Why have thorium fueled nuclear reactors not been more fully developed?
Why have thorium nuclear reactors not been ore fully developed? Earth has more thorium than uranium. Is it technical difficulties or the fact that uranium technology was developed first for military reasons? Are there other reasons?
Brinn Belyea
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Are there any differences between using nylon or ABS for RF electronic cases?
I want to contain a very small PCB (roughly a square centimetre) in a casing. For demonstration purposes I want to 3D print a couple of those casings as well.
The most obvious method available would be using ABS for the printed casings. However,…
Mast
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6
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1 answer
Why do boiler exhaust stacks use tapered transitions?
We have a boiler exhaust stack with a base dimension of 120" ID and an overall height of 84'. 21' up, the stack begins a slow transition to 7'6" ID. The transition takes approximately 35' to reach its smallest diameter in the stack.
In designing…
Lawrence
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6
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What happens to silicone gaskets (siloxane rubber) in presence of ethylene glycol?
Normal sealings and gaskets are made from NBR for use in conjunction with aqueous solutions of ethylene glycol which are common coolants for various purposes.
However to keep sulphur out of a cooling system and the surrounding area I want to change…
Ariser
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6
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How should one model a structural model with both line elements and area elements?
I am modelling my structure using FEM, and my structure contains line elements (1D) such as beams and columns and area elements (2D) such as walls and columns.
My question is that, how can I proceed to do modelling, and how can I interpret the…
Graviton
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6
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Thrust consideration in sprinkler and irrigation systems
In commercial fire sprinkler systems or large farm irrigation systems, is the thrust produced by the water a major design consideration? At what stage in the design process is this taken into account?
agentroadkill
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6
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1 answer
What is the equation to calculate the Thrust coefficient within a set of parameters?
In the book, Design of Liquid-Propellant Rocket Engines, there is a practice problem written as such.
"Determine the design values of $(C_*), (C_f), and (I_s)_t$ for the engine thrust chambers of the stages of the hypothetical Alpha vehicle, with…
fftk4323
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