Charles Dodgson who wrote the wonderful book Alice's Adventures in Wonderland under the pen name Lewis Carroll was a mathematician by training and practice. His book was admirably illustrated by Sir John Tenniel. Dodgson made some good strides in mathematical logic, linear algebra, and matrix operations. Of course, who doesn't remember who Alice spotted one fine day and decided to follow.
I've gone back and cleaned up my basic SIR Model as described in a previous post. I have added some features and put some more thought into it. I hope to describe it here and what might be some of the ramifications. Given the current state of political affairs here in the United States and being the election season it has helped me wade through some of the effluvia that is always present in politics. Especially concerning this matter.
From the first post in this series I wrote about determining the performance of an explosive using the Cylinder Expansion test, or Cylex as it's commonly known. As I mentioned the radial velocity of an expanding cylinder (copper for the cylex test) is measured. This is done a number of different ways. The earliest method used a streak camera.
This is the first part of a series on the properties and application of explosive materials. I suppose the first thing to do is define some terms. An explosive is any system, gas, liquid, or solid, that will propagate a supersonic wave front at a characteristic velocity that is supported by chemical reaction. A graphical relationship helps to show this.
Much of my work over the years involved testing and developing explosive systems. What I hope to do with this series of posts is to describe in a succinct form some of the background, both theoretical and experimental, that went into my work. This series of posts is an overview of explosive materials and their uses. It's similar to some texts available but I will be including links and various downloadable items that some readers might find useful.
There are three basic types of explosive materials: primaries like azides and fulminates; secondaries such as HMX, RDX, and TNT; commercial, which include variants of ammonium nitrate/fuel oil used in the mining industry.
Now that I've cured and tacked out the Mojave Green skin there seems to be some debate over who gets the resulting product. Isn't that always the case once the work is done?
Meanwhile the skin is drying nicely. I make sure the skin is up off the board so that air can circulate freely.
I've been exploring the model space and it's a dark, cold place. You can get lost out there. I developed a basic SIR model for disease transmission and recovery and set out to turn the knobs on the values. Recall the original model looked like the graph below. What you can see is that the blue line is very nearly at zero and the green line is approaching 1000 or the total population that I used.
The blue line being very nearly zero means there are very few members of the population left that are susceptible to the disease. The red line indicates the infectious which are the people currently suffering from infection and potential death. "Flattening the curve" is spreading out the red line in time which can be accomplished by reducing the transmission rate (social distancing.)
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