dynode.nl – Page 15 – keratoconus, electronica en diverse onderwerpen

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New geiger counter build

Posted on July 7, 2012 7:56 pm by Johan

I’m currently building a GM counter for a friend and was looking for nice, low
power circuits working on 9V cells.

I found this circuit which is derivative of Charles Wenzel’s designs:

http://www.mikrocontroller.net/attachment/103170/Geiger_Hochspannung.png

Components are fairly basic apart from the HV transistor and zeners. The other
transistors can be basically any small signal PNP/NPN transistor from the
junkbox. I used BC547 and BC557 and a MPSA44 HV transistor. Continue reading → Post ID 1068

📂This entry was posted in Electronica english wetenschap/science 📎and tagged Electronica english geiger counter high voltage radioactivity soldering
Baerveldt implant update

Posted on June 23, 2012 4:00 pm by Johan

English summary below as usual

Het is nu ongeveer 2 ½ maand geleden dat mijn rechteroog van een Baerveldt implantaat is voorzien om de te hoog opgelopen oogdruk onder controle te krijgen. Door lang gebruik van corticosteroïden is er secundaire glaucoom opgetreden welke een klein defect in mijn zichtveld rechts heeft veroorzaakt.

Bij een Baerveldt implantaat zal de oogdruk na de operatie behoorlijk variëren, en dat heb ik ook gemerkt. Na de operatie was deze redelijk hoog, tot 28 mmHg en zakte deze weg naar rond de 20 en bij het opengaan van het buisje naar rond de 10. Vooral dit laatste was duidelijk merkbaar, door de plotselinge drukverandering had ik opeens een soort donkere vlek onderin mijn zichtsveld zitten. Volgens het ziekenhuis waar ik snel voor controle langs ging was er verder niks aan de hand met het oog. Continue reading → Post ID 1068

📂This entry was posted in keratoconus medisch/medical 📎and tagged baerveldt corneal transplant english glaucoma glaucoom hoornvliestransplantatie keratoconus oog
Some info on getting started with radiation detection

Posted on May 23, 2012 2:06 pm by Johan

Quite a lot of the posts on this weblog are about radiation. To summarize some of the information I decided to write this post.

Geiger Counters

If you want to detect some radiation it is the easiest to buy a simple geiger counter. On eBay various geiger counters are sold for varying prices. Also check out the links at the end of the article. Possible options are: Continue reading → Post ID 1068

📂This entry was posted in Electronica english wetenschap/science
GS-1100A2 teardown and review

Posted on May 12, 2012 8:58 pm by Johan

The Australian company Bee Research offers the Gamma Spectacular USB powered scintillation probe bias supplies with integrated preamplifier and audio output. With this box, a scintillation detector and the excellent free PRA software it is possible to perform some basic gamma spectrometry far cheaper than obtaining a multichannel analyser, which usually cost thousands of dollars/euros.

I bought one of these from a Yahoo groups Gamma spectrometry member out of curiosity. What’s in this little box? Continue reading → Post ID 1068

📂This entry was posted in Electronica english wetenschap/science 📎and tagged Electronica english gammaspectroscopy radioactiviteit radioactivity science scintillation detector
Most fearsome medical treatments

Posted on May 6, 2012 2:42 pm by Johan

I have a more than healthy interest in medical procedures. When I have something or hear from somebody having some sort of serious illness I read up on it. Most stuff is just interesting, but some treatments cause me to fear and respect medicine. Here are some of the treatments I will hopefully never need:

(please note, I am not a doctor, consult one for official opinions on these procedures)

Heart transplant

A heart transplantation is performed when a heart is no longer able to support the patients body. The new heart is harvested from someone who has recently deceased and is kept on artificial circulation to keep the heart in good condition. When the surgery is near, the heart is stopped and put on ice. The patient is put on cardiopulmonary bypass which means that circulation and oxygenation of the blood is done with a heart-lung machine. The old heart is removed, the new one put into its place and connected to the main veins and arteries. The heart is then restarted and from then on handles circulation in its new body. Continue reading → Post ID 1068

📂This entry was posted in english medisch/medical wetenschap/science 📎and tagged cancer fearsome medisch/medical radioactivity respect

New geiger counter build

Baerveldt implant update

Some info on getting started with radiation detection

Geiger Counters

GS-1100A2 teardown and review

Most fearsome medical treatments

Heart transplant