This past week has been all about calibration.
You see - the McMurtry Lab at UH Manoa is building a field-deployable mass spectrometer. This is an instrument that is used to measure a large range of molecules that exist in gases. The gases can either be gaseous, or dissolved in a solution like water.
What are we using it for? Next week we'll be headed to Lassen Volcano in northern California to see if we can see any carbon dioxide in a plume, or fumarole, on that active volcano.
But, of course - things don't always go to plan. This instrument is sensitive. Most mass spectrometers are happily housed indoors in nice, climate controlled labs. This mass spec needs to be able to automatically suck in the outside gas, analyze it, and then repeat. A mass spectrometer needs to operate and very low vacuum - usually on the order of 10-8 for a good, clean signal.
So this week, everything is working. The system can run on auto like a champ. We have finished a routine that makes it able to flush itself with a new working sample. What's left to be done is to figure out how to calibrate the gas.
Gases can be measured either by mass or by volume. A 1000 ppm carbon dioxide is 1000 parts per million by volume. As of right now, our mass spec is still seeing more air than signal, which is very perplexing. I hope to figure it out soon!
Friday, August 24, 2012
Monday, May 7, 2012
The new consciousness of money
Two simple things that the modern man takes for granted: money and time. In the last week, I have considered how the two abstractions have changed human life and experience radically. It is funny how once you have an idea, it seems to cycle through your mind and conversations. In this post I will first address money.
It began with the thought that in the past, and certainly in some parts of the world today (or parts of society), there was two ways to build capital. First, to have land. Land and property were something that could be passed generation to generation, could be profited from through trade and non-monetary "rent". If you have land that is yours, you have secured for yourself one part in the food, water, shelter equation that is necessary for basic existence.
Second, you build your wealth by having children. Children used to be profitable, in a sense. Not only would they care for you in your old age, but the daughters could earn a dowry for your family (or the sons, depending on the culture). Children could work the land you have, farm the land you rent, or be the "minimum wage workers" of today's society. The more children you had, generally the more wealthy you had the potential to be, up to a point.
The modern society has entirely changed this equation. Wealth is judged almost entirely by a single abstract metric - money - that allows you to purchase the food, water and shelter you need. While land is still a form of wealth, you could be very wealthy without owning land. You can be wealthy today without actually producing any product at all (and in this service economy, that is all the more true).
It began with the thought that in the past, and certainly in some parts of the world today (or parts of society), there was two ways to build capital. First, to have land. Land and property were something that could be passed generation to generation, could be profited from through trade and non-monetary "rent". If you have land that is yours, you have secured for yourself one part in the food, water, shelter equation that is necessary for basic existence.
Second, you build your wealth by having children. Children used to be profitable, in a sense. Not only would they care for you in your old age, but the daughters could earn a dowry for your family (or the sons, depending on the culture). Children could work the land you have, farm the land you rent, or be the "minimum wage workers" of today's society. The more children you had, generally the more wealthy you had the potential to be, up to a point.
The modern society has entirely changed this equation. Wealth is judged almost entirely by a single abstract metric - money - that allows you to purchase the food, water and shelter you need. While land is still a form of wealth, you could be very wealthy without owning land. You can be wealthy today without actually producing any product at all (and in this service economy, that is all the more true).
Monday, April 30, 2012
Wikipedia
My first wikipedia post. On googling, there was only a sad inaccurate stub in place for wave setup. A rather encyclopedic entry today, I think:
In fluid dynamics, wave setup is the change in mean water level due to the presence of waves. This setup is present in and near the coastal surf zone, and is evidenced by a rise in mean sea level above the still water line.
Wave setup can be mathematically modeled by considering the variation in radiation stress (Longuet-Higgins & Stewart 1962) in the longshore and cross shore directions. As a progressive wave approaches shore and the water height decreases, there is additional flux of horizontal momentum due to the bottom pressure, but the energy remains constant. The additional flux is balanced by a decrease in the mean water level before the waves break, called a "set down".
After the waves break (see breaking wave), the energy is no longer constant, but decreasing due to energy dissipation after the break point. The radiation stress therefore decreases, and the free surface height increases to balance, causing wave setup. Both of the above descriptions are specifically for beaches with low slope. As the wave approaches shore, the higher mean sea level may lead to wave run-up on the beach.
Wave setup and wave run-up are particularly of concern during storm events, when the effects of big waves generated by wind from the storm are able to do damage to coastal infrastructure because of wave setup and a corresponding increase in mean sea level.
In fluid dynamics, wave setup is the change in mean water level due to the presence of waves. This setup is present in and near the coastal surf zone, and is evidenced by a rise in mean sea level above the still water line.
Wave setup can be mathematically modeled by considering the variation in radiation stress (Longuet-Higgins & Stewart 1962) in the longshore and cross shore directions. As a progressive wave approaches shore and the water height decreases, there is additional flux of horizontal momentum due to the bottom pressure, but the energy remains constant. The additional flux is balanced by a decrease in the mean water level before the waves break, called a "set down".
After the waves break (see breaking wave), the energy is no longer constant, but decreasing due to energy dissipation after the break point. The radiation stress therefore decreases, and the free surface height increases to balance, causing wave setup. Both of the above descriptions are specifically for beaches with low slope. As the wave approaches shore, the higher mean sea level may lead to wave run-up on the beach.
Wave setup and wave run-up are particularly of concern during storm events, when the effects of big waves generated by wind from the storm are able to do damage to coastal infrastructure because of wave setup and a corresponding increase in mean sea level.
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