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1500 questions
12
votes
1 answer
Why are typical UART baud rates not in multiples of 1000?
Why are typical baud rates not in multiples of 1000 instead of being in multiples of 300 i.e. 4800, 9600, 19200, 115200, etc...? Is there a mathematical or electrical reason behind this?
prasad
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12
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7 answers
Why does a gear have extra holes?
In a gear you normally have a center hole for the shaft to be put into. Why do some gears have holes surrounding that center hole?
Is it for weight reasons? Does it add stability? Is it so you can add special parts?
Mat NX
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12
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3 answers
Thermoelectric Technology to Harvest Energy from Internal Combustions Engines
Background:
In an automobile, only 1/3 of the potential energy in the fuel is converted into mechanical energy and significant portion of the energy is lost as heat.
There have been previous attempts to recuperate this lost energy. In the early…
Mahendra Gunawardena
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4 answers
How do I calculate the forces on a desk and its legs?
I have a design for a desk, and I'd like to not just guess at how strong it'll be, but I can't find an explanation on how to figure out all the forces involved that doesn't assume I already know a lot about engineering already.
So, if I were to…
mordac
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12
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1 answer
What is the meaning of vorticity and circulation?
In fluid kinematics I can't understand the meaning of these terms : vorticity and circulation.
Can somebody give me a description of these terms so that a lay person can understand them easily?
M.Tarun
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12
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2 answers
Does a Faraday cage effectively act as a notch filter?
In reading about Faraday cages, I have found that most "real world" designs incorporate multiple layers of mesh. For example, this article from the National High Magnetic Field Lab discusses several different shielded rooms built of varying…
user16
12
votes
4 answers
Why is oil used as the lubricant in power generators, while water is the most available, cheapest and accessible lubricant?
The lower viscosity of water reduces friction. Besides, the water can transfer heat way better than oils. So why not use water as a lubricant in wind or hydro turbines, especially on equipment which is operating in the ocean ...
It seems to be a…
Sam B
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1 answer
How can Pareto Analysis help solve engineering problems?
Attach is a Pareto Diagram with Number of Defects in Y-axis vs Causes in X-axis for an engine overheating problem. How can this Pareto diagram help an engineer solve the engine overheating problem?
Reference:
Pareto analysis
Mahendra Gunawardena
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12
votes
1 answer
Insufficiently constrained structural model in Ansys
I want to analyze this model that is stressed and deformed. I fixed the lowest of points in the x, y, and z directions, and I pulled top of points upward (y direction). When I run the model in Ansys I got the following error:
Check for…
Bae
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12
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5 answers
Low cost, moderately accurate water depth measurement
tl;dr: After an extended conversation with an old-timer, I realized a few things:
The single most valuable measurement for the majority of people will be water-depth-in-well.
The second most valuable will be water-flow-from-well.
The "bubbler"…
Peter Rowell
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12
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1 answer
What are the lightest springs?
I am wondering if there is a spring strong enough and light enough to inflate an airtight membrane so that it floats at Standard Temp & Pressure.
As an example, a 10cm cylinder would displace just under 1 gram of air, but a cylindrical spring would…
feetwet
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12
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3 answers
Exploiting fluid dynamics for the optimal design for gas mixing in a furnace
Background
This is the standard design for a thermal furnace used in the Clauss process, which converts H2S to SO2. The main problem with the furnace is that gas mixing is rather poor and results in only a 60% conversion rate. This in turn…
22134484
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12
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2 answers
How long does it take for dust to settle out of the air?
In order to make this a manageable question, let's add a few simplifications.
The dust particles can be well described as uniform spheres of radius $R$ and density $\rho$.
The space is enclosed and there is no bulk flow, i.e the air is still in…
Chris Mueller
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12
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4 answers
Will more electricity be generated by using a lens to focus sunlight onto solar cells?
I have been wondering about this question for quite some time. Assuming an ideal case, the energy from photons hitting solar cells is converted into electric energy as described by the equation:
$RI^2t=W\equiv E=\hbar\nu$
where $\nu$ is the…
TBBT
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12
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5 answers
What is the difference between pressure and stress?
Since the units are the same ($\frac{N}{m^2}$), what's the difference between pressure and stress?
user133