Harvard Museum of Natural History

I really like spending part of a day at a museum. Thankfully, there are a bunch of them in the Boston area; including some really fascinating ones on the campus of Harvard University. Today, I visited the Harvard Museum of Natural History and saw a lot of interesting objects and curiosities. There were entire rooms filled with the works of multiple lifetimes; both in the various flora/fauna that filled the exhibition cabinets and the storied histories in the lives that were devoted towards taxonomy in the making of the museum.

A real American Beaver, the epitome of an MIT student in animal form

Lots of pictures of the museum, no flash, of course
https://photos.app.goo.gl/dXD3fs8kRfXxgYaW8

Back in Boston: Photos from Trip

My sleep schedule is a bit weird at the moment. Since I got back on the evening of the 16th, I have been falling asleep around 8pm and waking up at midnight, only to fall asleep again a few hours later and wake up at 9am. This is classic jet lag.

For my time back in my dorm, I'll be working on some projects like my ProjX funded electrolysis cell.

This is the picture of the SUTD and MIT students who worked on a group project in Singapore.




Photos from the trip by day (You'll notice I took significantly less photos near the end of the trip, some photos may be added later on)

January 6th
https://photos.app.goo.gl/Cc9jHfTvBy2X3F5WA
January 7th
https://photos.app.goo.gl/3nqQTUHqyrDyFxjJA
January 8th
https://photos.app.goo.gl/CZXQdM7CbE5xHyAb8
January 9th
https://photos.app.goo.gl/1TqYKdRyhZRB8QZw6
January 10th
https://photos.app.goo.gl/b73MLajrhGN5wjgXA
January 11th
https://photos.app.goo.gl/f5YQUHf8cGE8wBLFA
January 12th
https://photos.app.goo.gl/WEaWouPuk5ZaMFZWA
January 13th and 14th
https://photos.app.goo.gl/19E3wnTaBEddSmK39

First Pictures in Singapore

 My trip to Singapore has started off to a great set of sights. The condominium that I am staying at has a great set of amenities. The two first pictures here are of the pool at night and day.

 There is a wide variety of flowers with butterflies abundant in almost every patch of color. My friend Go mentioned that a lot of the green space in the city is "manufactured". This adjective represents the city's design fairly well. It seems almost every square inch of terrain has a engineered touch to it.

Yesterday, I got food at the White Sands mall with my friend Monica. Today, we are at the SUTD collaboration center to meet up with SUTD students for an informal hackathon.

CDV-700 Examination and Fix

 My former AP Chemistry teacher recently asked me to look at these two CDV-700 Model 68 Geiger counters he would use to talk about radioactivity in class. Back in the day, the American Nuclear Society's local branches in different states would distribute this particular model around to various schools.

The goal of these programs would be to provide students with a physical understanding of radioactivity. If I recall correctly, I remember seeing these exact devices in class when I was a student in high school a few years ago.

Now I am a student of nuclear science and engineering. So I guess the ANS project worked.

The two CDV-700 devices I was given to check over were not working properly. The first thing I did was open them up. Opening the CDV-700 is easy because the device was designed to be easy for hobbyist repairs, the top (including the meter and GM tube holder) comes off to expose the battery holders, circuit board, and level selector switch.

The manufacturer left a circuit diagram in the metal case. The circuit diagram includes troubleshooting points (locations in the circuit where certain DC voltages are expected). I found that the HV calibration was a little low. I was not sure if this was intentional or happened when somebody dropped the device. I reflowed the leads to the flyback transformer that creates a 900V standing rail for the GM tube.

When ionizing radiation enters the GM tube, it momentarily excites the gas in the enclosed tube. This causes a short circuit and the flyback transformer deposits some electrical energy into a circuit that both creates a pulse for a speaker as well as charges a needle in the device's meter. The amount of charge deposited to the needle (over a selected resistor for scale) is related to some amount of effective dose (in mR/hour).