Recent content by Aki

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    Finding upper and lower limits of a graph

    well I just made up that graph. I can't show the data that I'm working with because it's confidential. Anyhow, there are graphs where if I apply the Chebycheff's Inequality, I get a negative value for the lower limit.
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    Finding upper and lower limits of a graph

    Homework Statement This is not really a homework problem, but it looks like a rather easy problem that I can't quite figure out. So I have a graph like shown in the attachment: a quantity vs time graph with some data points. I had no problem finding the average, but now I want to find...
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    Proving bc=d for Cubic Function with r=-s

    Very helpful. Thanks a lot Gib Z
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    Proving bc=d for Cubic Function with r=-s

    Hey I need help with this proof: Consider the cubic function: x^3 + bx^2 + cx + d = 0 . If the two solutions of the cubic function are not equal, ie r != s, but r=-s, then prove that bc=d. Thanks
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    Choosing the Best Valve: Ball vs Solenoid for Reliable Flow Control

    Yes I know how to find the Cv for a fluid: Q=Cv*root(change in pressure / specific gravity) But I do not know how to find the Cv of a gas
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    Choosing the Best Valve: Ball vs Solenoid for Reliable Flow Control

    What would happen if I use a valve that has a Cv lower/larger than the one that I calculated?
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    Choosing the Best Valve: Ball vs Solenoid for Reliable Flow Control

    Would stainless steel be compatible with LOX, and what using brass for kerosene? Is true that ball valves in general are bigger than solenoid valves because ball valves need an extra actuator? I've looked at the Valcor cryogenic valves, and they either have a Cv that is too small or the...
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    Choosing the Best Valve: Ball vs Solenoid for Reliable Flow Control

    Thanks for your replies I'm building a LOX-Kerosene fueled rocket. I need some fuel that goes to the igniter for the first 10 seconds, and then the rest of the fuel goes to the main combustion chamber for 90seconds. The flow rates and other properties are: LOX: 1.5 L/s , -186 degree C ...
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    Choosing the Best Valve: Ball vs Solenoid for Reliable Flow Control

    Hi, I want to know the difference between an actuated ball valve and a solenoid valve. Which one is more reliable? I want to program the valve so that it allows flow for 10 seconds to one outlet and after that direct the flow to the second outlet. I know I'll probably need a 3-way valve...
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    Hi,I need to find a suitable material for o-rings for my rocket.

    Hi, I need to find a suitable material for o-rings for my rocket. It will be used in the mounting of a stainless steel combustion chamber, so I need the o-ring to be able to withstand high temperature and pressure. Any suggestions? Thanks
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    Need help igniting liquid fuel for rocket propulsion?

    I decided I am going to use a spark plug, and I have the Go-Ped Kicker spark plug in mind. Has anyone else used it before? http://www.msdpowersports.com/go-ped.html"
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    Need help igniting liquid fuel for rocket propulsion?

    Well to address everyone's concerns, this is an university student project team, and our goal is to build a reusable rocket capable of carrying a payload. We have obtained a permit from the Canadian rocketry association for launches. There are approximately 30 people working on this, and this...
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    Need help igniting liquid fuel for rocket propulsion?

    Okay, so I'm building a liquid propulsion rocket, about 4m tall, with a 2000lb trust. The propellants used are liquid oxygen and kerosene. Now the trouble is to find a way to ignite the fuels to start the combustion. Do you guys have any ideas? Thanks!
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    Exploring a Finite Universe: Understanding its Challenges

    So does the shape of our universe has anything to do with the Calabi-Yau theory?
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