Category Archives: Excel

Thermoelectric Cooler Calculation Example

Posted on 27-October-2017 by mathscinotes

My team is work hard on Dense Wavelength Division Multiplexing (DWDM) optical systems for communications applications. These systems put multiple wavelengths on a single fiber, and they provide our customers the opportunity to deliver significantly more bandwidth without needing to additional fiber optic cables. Continue reading →

Posted in Electronics, Excel, optics | 1 Comment

WW2 Tank Production Comparison Between Combatants

Posted on 22-September-2017 by mathscinotes

Quote of the Day At least you figured it out. My first two husbands never did. — Female employee told me this after I mentioned that my wife's nickname for me was "The Paycheck" – this nickname was a joke … Continue reading →

Posted in Excel, History Through Spreadsheets, Military History | 15 Comments

Examples of Lake Clarity Variation Over Time

Posted on 13-September-2017 by mathscinotes

I am having my cabin built on a small lake in northern Minnesota. At the same time that the cabin is being built, a friend is in the process of locating an an existing cabin for purchase on a nearby lake – there are dozens of lakes within a few miles of my building site. He has been asking questions about the clarity of the water in these lakes. Fortunately, the state of Minnesota has an excellent web page with all sorts of technical data on lake water, including clarity measurements. Professional lake monitors are also used. On a regular basis, they gather technical information on the lakes: chemistry, fish populations, presence of invasive species, etc. The lake water clarity data historically has been measured using a Secchi disk (Figure 1) and volunteer lake monitors. In recent years, satellites have been tasked with clarity monitoring as well. So there are now two sources of lake clarity information that can be used to cross-check one another. Continue reading →

Posted in Excel, General Science | Comments Off on Examples of Lake Clarity Variation Over Time

Hurricanes and Typhoons Ranked By Air Pressure

Posted on 7-September-2017 by mathscinotes

I was watching the weather reports on Hurricane Erma and the discussions on how powerful it is. The most cited metrics for hurricanes and typhoons appears to be wind speed and eye barometric pressure (see Figure 1). I decided to look around for hurricane and typhoon strength data and the Wikipedia turned out to have a page containing large number of tables for all the most intense typhoons and hurricanes in different regions of the world. I used Power Query to (1) import the tables, (2) clean them up, (3) combine them, and (4) rank the storms by air pressure. Continue reading →

Posted in Excel, History Through Spreadsheets | Comments Off on Hurricanes and Typhoons Ranked By Air Pressure

Largest Counties in the US

Posted on 30-August-2017 by mathscinotes

I am currently building a retirement home in Itasca County, Minnesota. While at the construction site, I spoke with with a sheriff's deputy about law enforcement coverage for my area. He told me that there were only two deputies on duty at night covering an area larger than the state of Delaware. He also said that if I the deputies are tied up in the southern part of the county it can take a while for them to get to my place, which is in the the northern part of the county. I had never thought about the size of the counties in northern Minnesota, but there are some large pieces of real estate there. Continue reading →

Posted in Excel, Personal | Comments Off on Largest Counties in the US

US Navy Warship Mix

Posted on 24-August-2017 by mathscinotes

While driving home after watching the eclipse, I listened to the news talking about a collision between a US Navy destroyer, the USS John S. McCain (Figure 1), and a commercial tanker.  A previous collision also involved a destroyer, the USS Fitzgerald. These stories have made me curious about how many of these ships the US Navy has.  Continue reading →

Posted in Excel, Military History | Comments Off on US Navy Warship Mix

US Farmland % By State

Posted on 2-August-2017 by mathscinotes

I am preparing to drive out to Idaho to experience totality during the August 21, 2017 eclipse. I am choosing to view the eclipse from Idaho because my granddaughter (and her parents) live in western Montana, and I can stop there for visit when I return to Minnesota. This will be a long drive through large states (Minnesota, North Dakota, Montana) that have a significant percentage of farm land. While planning my journey, I became curious as to the percentage of farmland in each of the fifty states. In this post, I compute the farm land percentage by taking the farm acreage in each state and dividing by the state's land area (water area removed). Continue reading →

Posted in Excel | 5 Comments

An Example of Cleaning Untidy Data with Tidyr

Posted on 20-February-2017 by mathscinotes

I recently decided to take some classes in data analysis at Datacamp, an online training site. My first classes were in dplyr and tidyr – two excellent R-based tools for manipulating files that not amenable to analysis because of inconsistencies and structure: tidyr provides many tools for cleaning up messy data, dplyr provides many tools for restructuring data. After completing the two classes, I decided that I needed to firm up my knowledge of these tools by applying them to a concrete example. Continue reading →

Posted in Excel, History Through Spreadsheets | 2 Comments

Quick Look at Large US Dams

Posted on 17-February-2017 by mathscinotes

I was on the phone this morning with a coworker who lives in California, about 150 miles south of the Oroville dam (Figure 1). This dam has recently been in the news because of concerns that spillway erosion could cause a dam failure. At one point, nearly 200K people were evacuated from the potential flood zone. Continue reading →

Posted in Excel, History of Science and Technology | 3 Comments

Fact Checking: US Murder Rate Over Time

Posted on 13-February-2017 by mathscinotes

I recently saw a politician claim that the US murder rate is the "highest it's been in 47 years." This is an easy fact to check and provided me another Power Query example to provide for my staff. Continue reading →

Posted in Excel, Fact Checking | 2 Comments