Monthly Archives: March 2016

Converting Specific Humidity to Relative Humidity

I often have to interpret odd test requirements. In a test specification based on GR-487, a humidity test is called out where we need to have a fixed specific humidity (i.e. 24 grams of water vapor per per kilogram of air). For a given specific humidity, the relative humidity will vary with temperature. Since my test gear can control relative humidity, I need to derive a relationship between relative humidity and the specific humidity, which I show in Figure 1. Continue reading

 
Posted in General Science | 7 Comments

Nuclear Spent Fuel Annual Generation Rate

A coworker was telling me about a relative of his who is an engineer at a nuclear power plant. One of his relative's many jobs is to babysit nuclear waste casks (Figure 1) – a task which includes monitoring their temperature. These casks are warmed from the inside by the radioactive decay of the waste they hold. As I understand it, this job has good long-term security because these casks are going to be a safety hazard for tens of thousands of years. Continue reading

 
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Power Plant Conversion Efficiencies

While crawling around the Energy Information Administration (EIA) web page, I found some data on the energy conversion efficiencies of power plants based on the fuel that they use. I thought the data was interesting and worth going through here. Continue reading

 
Posted in General Science | 1 Comment

Deer Crossing Signs Are for People, Not Deer

My sister sent me this link about a phone call to a radio call-in show. The woman on the call does not realize that deer crossing signs are warnings for people and are not instructions for deer. You might think this is a joke, but I have heard real people having this discussion. Continue reading

 
Posted in Humor | 3 Comments

Churchill's Plea for Brevity

I am stunned at the length of the product specifications I have to deal with today. Not many years ago, a laser driver specification might have 20 pages of text. Today, it is not unknown for a laser driver specification to go on for hundreds of pages. I really wish documents were shorter. I actually believe that the word processor has enabled people to write more with way too much ease. Continue reading

 
Posted in Technical Writing | 1 Comment

Decision Making Using the Analytic Hierarchy Process

I gave a seminar a few days ago on System Engineering – a favorite subject of mine. One of the topics covered during my System Engineering seminar was decision making. Specifically, I speak about how I want trade studies to be performed in my group. I have participated in hundreds of trade studies, and I have used many different approaches. Continue reading

 
Posted in General Mathematics, Management | Leave a comment

Circuit Analysis Using a Two-Port Transformation

I was doing some reading on the Planet Analog web site when I encountered an interesting blog post by Dennis Feucht on a simple BJT-based voltage regulator with an output current limit. Continue reading

 
Posted in Electronics | 2 Comments

Lessons from RP Feynman

There is almost a cottage industry in RP Feynman quotes and stories. For an engineer, there is much gold to mined in his problem-solving methods. I read his book Surely You're Joking Mr. Feynman, and I have treated him as source of inspiration ever since. I was drawn to the joy he expressed about solving problems, and his skill in sharing that joy. Continue reading

 
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State GDPs Relative to National GDPs

I am amazed at all the different lists on the Wikipedia. Today, I came across a list of all the US state GDPs and a map (Figure 1) that shows how the state GDPs compare to the GDPs of various nations. I have to admit that I think this is a very interesting chart. Continue reading

 
Posted in software | 2 Comments

Typical Field Deployment Issues

I was looking at some photographs of a fiber-optic deployment, and I thought you might find it interesting seeing the details of what goes into the "green yard furniture" that quietly sits in the yards of many people (Figure 1). The fiber electronics is slung on a metal bar above the hole in the ground – all the cabling comes up from the hole. The plastic green cover behind the hole is intended to provide some environmental protection and a decent appearance. Continue reading

 
Posted in Fiber Optics | 1 Comment