August 4th, 2014
I’m now set up for kegging beer, and am putting a brown ale into a keg. I want to hurry things along. Kegging usually takes 1-2 weeks, but I want the beer ready in 5 days. To speed things along, I’m doubling the pressure to 20 psi for the first two days, lowing the temperature, and shaking the keg a few times a day. After the first two days, I’ll reduce pressure to 10 psi. If I shake it after that and CO2 still goes in, I haven’t over carbonated. I’ll bring the temperature up to 38F the last day.
Here are instructions I found:
Kegging instructions
A carbonation table: Handy-Dandy Slow Force Carbonation Chart featuring Pressure vs. Temperature
Getting A Good Pour – Kegged Beer CO2 Line Length and Pressure
Cold and a long tap line help reduce foaming.
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April 2nd, 2014
Have the time displayed by colored liquids in glass tubes, either a column of liquid or a large segment. The time tube can be straight or circular.
Move the liquid by a mechanism where brass gears compress a bellows. The brass mechanism would be driven by a microcontroller.
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March 30th, 2014
The motors made for RC planes and cars are high speed and high power.
For example, the Turnigy Trackstar 1/10 12.0T 3300KV Brushless Motor, $23 specs are:
Kv: 3300
Max Voltage: 15v
Max current: 35amps
Watts: 550
Resistance: 0.0221Ohms
Max RPM: 50000
The load on a microfuge will be greater–22 tubes x 1.5 ml can be roughly 44g, figure a 100g total load with the rotor. So slower than max, but still quite fast.
High power ESC modules are sold to run these motors. So they take DC power, and a servo like signal (PWM), +5, GRD.
So a 10k RPM microfuge can be made with one of these motors + ESC, a servo for locking the lid, and a microcontroller to run it, take speed / time settings, and monitor and show the RPMs on a display.
Power could be from a PC power supply or a dedicated supply.
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March 2nd, 2014
Could new measures substantially improve public health?
What would be the effect if, say, 90% of the country wore filter masks for one week, and concentrated on washing hands?
Infection is a chain, one individual infects one or more others, and an infection gets passed on. That is how disease persists–for most infectious agents, not in one person for months on end, but passed serially every few months as an individual gets infected, and over a few weeks mounts an immune response and fights it off.
An infectious agent requires a basic reproduction factor, an R0, of more than one. If R0 > 1, an infection is growing more common, if R0 < 1, an infection is disappearing. For more diseases, for infection to persist it must spread.
Currently there are constant but weak efforts to reduce the spread of infection–encouraging the sick to stay home and hand washing. Vaccines for influenza. But what if a serious effort was made? A big effort could not be sustained, at least not in the US culture.
But what would be the effect of a large, short effort? If infection transmission can be stomped down for a short period, but long enough to break the chain of infection, it might have a large effect on public health. I wonder if this has been modeled?
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