While this post does not address a math problem, it does address an important aspect of mathematics -- the presentation of data. I occasionally have to prepare information on various items for our Customer Service group. For a number of years, I have maintained a graphic that shows the average cost of a kW-hr of energy by state. Our customers use this data to estimate the yearly operating cost of our equipment in their deployments. I get the statistics from the Department of Energy (DoE) Website. It is a hassle to manually update all 50 states and DC, so I use a spreadsheet to link the data I download from the DoE to Visio. It gives me the graphic you see below. I got the original map of North America from the Visguy website.
I actually use this approach to update a number of graphics. I thought it may be useful for me to include it here as a model for people to use when linking Excel data to Visio. I have included a link at the bottom of this post to a zip file that contains the Excel spreadsheet and Visio drawing I use. When you extract the files, they will go into a directory called "North America." Just run the Visio file from that directory. It should be able to find the spreadsheet. I do not know how to setup a relative address in Windows, but this works on my machines.
You can force an update of the graphic by going to the Visio data tab and clicking refresh all.
Here is my source material: NorthAmerica.zip
Have you tried this approach with LucidChart? I am not. a Visio user, but know that it is compatible to some extent. I really like LucidChart and they provide it for free for teachers!
I have not tried LucidChart, but I will take a look today. Thanks for the reference. I am always looking for better tools.
Oh that will be handy... keeping my flow diagram (visio) and stream table (excel) in sync automatically would save me a bit of time!
Most of my stuff involves geographic regions: states, sales regions, specific market segments, etc. However, the same approach works for a lot of things.
You mention steam ... I actually have a problem that I would like to discuss with you. I have been doing some work on torpedoes used during World War II. I have been trying to model the variation in torpedo speed with depth. The back pressure of the water against the exhaust slows the torpedo, which use a form of steam engine (alcohol and air burned with injected water to produce steam). I was in a chat room when a person gave me a clue on how to model the performance, which I summarized here. Is that analysis reasonable?
Actually I said stReam table, not steam table, but I'll take a closer look at it some time when I'm not about to head out the door to work.
Sorry for the misread (I was moving pretty fast). Thanks for the offer to check.
If the assumption of constant steam mass consumption regardless of depth is correct, then it looks reasonable as a simple factor. I have no idea if that calculation would hold for other depths though, because I am not familiar with steam turbine calculations and particularly how sensitive they are to exhaust pressure changes. Although you do have 2nmi in the equation and 2km in the description 🙂
I was curious about one of the other comments on that page about underwater firearms however. Not knowing anything about underwater weapons, would those be more or less a bullet propelled by expanding gases as regular guns are? If so they don't have an exhaust in the sense that the torpedo you were looking at has, but they still rely on expanding gases and thus would be very susceptible to pressure effects on those, reducing the initial velocity substantially. I'd be surprised if the drag increased that much with depth; it's a solid object moving through an incompressible fluid.
I just saw that I missed your comment -- years ago. Thanks for catching the comment error, which I have fixed.
As far as underwater firearms, I know very little. I have heard that the Russians have done work using supercavitating projectiles (torpedo example). I also read somewhere that they developed and have been marketing a supercavitating "rifle" for use underwater. I have no info on it.
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