Hello, world! It’s been awhile since I’ve posted, but in that time I have completed a 141-page junior monstrosity of a thesis, which will shortly be published, stuck up on a shelf, and gather lots of dust. I’m not really being cynical; this is just what happens.
It’s nice to have a chance to catch my breath. Last week, my defense was on Wednesday, and the “Exam Only” (meaning that I only had to defend this semester) deposit deadline was that Friday, so the 48 hours in between the two were rather hectic. This was partly due to changes/corrections requested by my committee, and also to the formatting regulations imposed by the graduate school.
I went hiking with a few friends on Saturday, and will post those pictures when I have time. For now, I’ve been enjoying the chance to sleep and read books that have absolutely nothing to do with hydrazine!
However, I’ve not been entirely a bum. I have an interview with Aerojet next week, hopefully a phone conversation with GE Global Research at some point, and am preparing some materials that SpaceX has requested a look at. Hopefully some of these opportunities will come to fruition, so please keep them in your prayers.
More to come!
Dear Family and Friends, especially the ones who care about me,
Just a quick update on what will be going in my life:
My schedule for getting my thesis and research done was really cramped, and my advisor decided I was accelerating the process too much, so I’m now looking at an official graduation date in December 2011. I should be defending sometime before mid-October.
Thanks very much to all of you who have been praying for me. I’m mostly glad I have some more time; I’d rather turn out quality work than a rushed, half-finished job. It will also give me more time to look for a job, which has kind of fallen by the wayside as I’ve been pushing my thesis through.
I feel like I suddenly have a summer vacation! I’ll be in Texas for a week in July and in San Diego at the beginning of August, if anybody wants to find a time to catch up.
Please be in prayer for:
- Me finding housing/a roommate – everybody around here leases for a year at a time only
- My experiments getting done
- My sisters finding housing/transportation at their respective new schools.
But Mousie, thou are no thy-lane,
In proving foresight may be vain:
The best laid schemes o’ Mice an’ Men,
Gang aft agley
I haven’t posted in awhile, so here’s a lit review.
The decomposition and oxidation of hydrazine has been a topic of scientific interest for at least eighty years. Early studies, such as those by Askey or Bamford, focused on the vapor phase. Bamford noted that the chemical exploded when sparked or heated.
Audrieth noted much interest in low-concentration (~30%) hydrazine as a fuel in the years after World War II, writing that, “The hydrogen peroxide-hydrazine combination was first utilized by the Germans as a rocket fuel and represents one of the most promising bi-fuels for long-range high-altitude missiles.” He also documented that this combination appeared to be “self-starting”. In the same year, 1951, a paper by Murray and Hall recorded the observation of a 93% hydrazine flame. They described “possibly two inner cones, separated from one another by a very small distance.” This is extremely interesting to note in light of the dual-flame phenomena for droplets, although the authors attributed the second cone to “radiation from reaction products”. Continue reading
Monomethyl hydrazine is based on hydrazine, which has the chemical formula N2H4. Hydrazine is also used as a propellant and is both unstable and toxic. It may be used as monopropellant (usually after being run through an appropriate catalyst bed), or more commonly as a bipropellant, being hypergolic with nitrogen tetroxide (NTO). Applications of hydrazine have included propelling the Me163B (the first rocket-powered fighter, WWII), on the Viking and Phoenix lander descent engines, and powering F-16 emergency power units. Notably, the thrusters on the spy satellite USA 193 were fueled with hydrazine; an interesting article on the role of hydrazine in the satellite shootdown is here: http://spectrum.ieee.org/aerospace/satellites/us-satellite-shootdown-the-inside-story
Monomethyl hydrazine (MMH) is the result of replacing one of the hydrogens in hydrazine with a methyl group, CH3. It is more stable than hydrazine (can be used in regeneratively cooled engines), and is thus favored as a storable propellant. Because it is still toxic, as well as a suspected carcinogen, great care is taken in handling it. It is most commonly used in hypergolic combination with NTO, such as in the Space Shuttle’s Reaction Control System (thrusters). MMH decomposes into mainly H2, with some CH4, N2, and trace amounts of NH3 and C (soot).
“First of all,” my sister writes, “you should post on what your project is/is trying to accomplish.” … All right, my objective: Characterize the behavior of dual flame fronts in gelled MMH/gaseous NTO as NTO diluent partial pressure and type vary.
This is the simplest way to summarize my project while still preserving the technical aspect. It does, however, lead to a slew of questions: What is involved in “characterizing”? What is a dual flame front? What do MMH and NTO stand for and what are they? Why would you gel them? Why is diluent involved and what am I using? And how does this help babies in Africa?
Summer is here! Last summer I tried to step up my posts to once a week, writing on topics suggested by you, my beloved readers. I’m inclined to be less democratic this year. Who cares for the whims of the general populace? I have a thesis to write – and this blog is going to help me. At least, that’s the plan.
Hold me to it: one post per week on some topic related to what I need to cover in my thesis. It will have to be pretty high-level, but at least I’ll be generating content that I can use in some fashion, and it’ll make me think about the “bigger picture”.
If you do feel the dire need to request a post on something, I might be able to satisfy your search for information. We’ll see.
Speaking of thes(es?), this is great: [preface]
“Sometimes a scream is better than a thesis.” -Manfred Eigen
Below are some photos from a typical testing day. This is mainly for my family or other people who wonder what I’m doing when I say, “I have to go to work”, or, “I got to make fire yesterday.”
The dry box: actually stocks invented for chemists. It allows us to maintain a nitrogen environment for things that don't like oxygen.