Tuesday, November 28, 2006

Ahh, Texas II

One of the things I miss about California is the quaint state politics, like the Peace and Freedom Party, which doesn't sound too bad ("Hey - I like peace and freedom!") until you realize that they're radical Marxists. Texas provides its own amusement, though. From this morning's Houston Chronicle:

AUSTIN A Texas official who receives any sum of cash as a gift can satisfy state disclosure laws by reporting the money simply as "currency," without specifying the amount, the Texas Ethics Commission reiterated Monday.

The 5-3 decision outraged watchdog groups and some officials who unabashedly accused the commission of failing to enforce state campaign finance laws.

"What the Ethics Commission has done is legalize bribery in the state of Texas. We call on the commission to resign en masse," said Tom "Smitty" Smith, who heads Texas Citizen, an Austin-based group that advocates for campaign finance reform.

Thank goodness I live in a state where officials are allowed to take suitcases full of cash, and it's ok as long as they write down "currency" on their ethics disclosure forms. Wow.

Friday, November 24, 2006

A good scientific interaction

The science: one of my colleagues, Prof. Vicki Colvin, can make magnetite nanoparticles via chemical techniques. Magnetite is an interesting material for a number of reasons, some of which I'll probably write about later. It's a ferrimagnet with a Curie temperature of over 800 K. Nanoparticles smaller than about 40 nm in diameter are single-domain, and those smaller than about 16 nm in diameter are superparamagnetic at room temperature. That means that while the spins are ferrimagnetically ordered, the energy required to reorient the magnetization direction of a given particle is less than the thermal energy scale, kT. Anyway, magnetic particles have been used in the chemical engineering world for a long time to do separations. Make magnetic particles that adsorb your favorite nasty contaminant of water; mix the particles in with the water, and then use large magnetic field gradients to pull the now-dirty particles out, leaving behind cleaned water. Just looking at the magnetic forces on individual magnetic particles tells you that nanoparticles shouldn't work well: the magnetic forces scale like diameter cubed, while viscous forces scale linearly with diameter, and Brownian forces scale like one over the diameter. However, she tried the separation process anyway using a little bench-top separator, and it worked exceedingly well! She asked me why, and after scratching my head for a little while, I realized that the key is actually interactions between the particles. The field gradients near single-domain nanoparticles can readily be 10000 times higher than externally applied gradients, leading to much larger forces than those due to the external field directly. To avoid permanent agglomeration of the particles, yet maximize separability at modest fields, one wants to use the biggest particles that are still single-domain superparamagnets. The real upside is that the nanoparticles have enormous specific surface area. So, a cleanup task that used to take a kilogram of big particles only needs a few grams of nanoparticles.

The sociology: Prof. Colvin could easily have written this up and just thanked me, rather than really inviting my participation and making me a co-author. Instead, she very much wanted my input and gave me ample opportunities to help in the writing of the manuscript. The result was a Science paper, and there is real promise (at least according to our environmental engineering coauthor, who is the expert on cost estimates and water purification) that variations of this work could greatly help in cleaning up arsenic-contaminated drinking water in the developing world. Very cool.

Tuesday, November 21, 2006

A bad scientific interaction.

The science: One of my collaborators supplies interesting molecules to lots of people. Six months ago, my student and I wrote up a paper on our measurements of some of these. We were pretty pleased with ourselves, because our data lets us make a pretty strong statement about the underlying conduction process in this system.

The sociology: While we wrote this up, a competing big group had been doing measurements on the same molecules with a very different technique. They reached the opposite conclusion as us in their case. At the suggestion of my chemistry colleague, we had a discussion about this with them once we both submitted our papers. There is some chance that we're both right, since the measurement systems are so different, so when we revised our paper, we allowed for that possibility. Our paper came out very quickly - five months ago. In the meantime, our competitors had a much longer review process (this doesn't necessarily say anything about their paper; review can be extremely variable.). Their paper just came out in a different journal. Not only is their wording much stronger than ours (basically stating that their suggested explanation is the only possible conclusion, period). They don't even reference our work, despite having known about it for several months. Not cool.

Saturday, November 18, 2006

A primer on faculty searches, part II

Continuing my description of the faculty search process.... Candidates come in for interviews. Each interview is a two-day affair. The candidate is scheduled to meet pretty much everyone on the search committee, and maybe a couple of other people in addition if there's time. Usually at 4:00pm on the first day, we have the candidate give a departmental colloquium. We point out to them when we invite them that the audience for our colloquia is very general - it can include undergrads, and the areas of research of the faculty members in the crowd can range from astrophysics to biophysics to high energy to AMO and CM. The point is we want to see how well the candidate communicates to a general audience about their work (usually their postdoc results, with a slide or a few at the end on future directions). After the talk is dinner with a couple of members of the committee. There are more visits on the second day. In the late morning (usually), the candidate sits down with the committee and gives a shorter (say 20 minutes) research plan talk. This is where the candidate tells us what they want to do in the near and longer term, and what kind of resources they think they'll need to do it (e.g. a big laser system, or a dilution refrigerator, or access to fab and microscopy tools, etc.). This is generally less formal than the colloquium, but it needs to be taken seriously, since this is really where the committee gets a sense of how the candidate approaches planning research. This is also where discussions about teaching happen. Depending on travel plans, there either is a second dinner, or the candidate heads out at the end of day 2.

Once the candidates have all visited, the committee sits down, compares notes, and comes up with a recommendation for the department to vote on. Once the department has made a decision, the department chair is the one who talks with the candidate about offer details. An unofficial offer letter is then prepared and sent out by the dean. Those in the game know what I mean by "unofficial": full-on offer letters come from the office of the president or the board of trustees, depending on the institution, and are essentially only prepared at the very last minute. The candidate is invited to come for a second visit - to look at lab and office space, meet the dean, bring the spouse or significant other if that's relevant, get a look at real estate, etc.

I'll write a third post about faculty searches with a few generic tips for candidates sometime soon.

Thursday, November 16, 2006

Weird Al is the man.

Watch this. It's Weird Al's new video. Bonus points for having the Schroedinger equation show up. This may be my favorite Weird Al song since The Saga Begins.

Sunday, November 12, 2006

CIAR Nanoelectronics workshop

Blogging from the scenic Calgary airport, as I wait for my flight back to Houston. I've been attending a very fun nanoelectronics workshop in Banff run by the Canadian Institute for Advanced Research. The CIAR is kind of an institute-without-walls that spans Canada. They have seven (I think) sections, each of which funds some research. One of these sections is Nanoelectronics, and the workshop this weekend was very good. Some highlights of the talks:
  • Ted Sargent at Toronto is making optoelectronic devices using semiconductor nanocrystals. His group has succeeded in getting nice surface passivation of PbS nanocrystals, such that they get good photoconductive response in a solution-deposited film of these things. Because the bandgap of the nanocrystals is so small (about 400 meV), they can use these in the mid-IR. In an impressive demo, they took a readout chip for a conventional silicon CCD camera, coated it with their PbS nanocrystals, and voila: instant visible-to-midIR video camera. Neat!
  • Supriyo Datta gave a nice talk about the general problem of modeling transport through a system that couples not just to its contacts, but also to the environment. As a story-telling device, he framed the discussion in terms of Maxwell's Demon: can one use the spin-selective transmission of a certain type of barrier (containing paramagnetic impurities) as a way of extracting work from the contacts? This is a solid-state gedanken version of Feyman's ratchet-and-pawl. Unsurprisingly, one can't beat the second law of thermodynamics. You can extract some work from the contacts, but at the cost of increasing the entropy of the barrier. If the barrier is cooled to allow work to be continuously extracted, what you've really done is set up a heat engine running on the temperature difference between the contacts and the barrier. I know this isn't a very coherent summary; the talk was infinitely more lucid.
  • Several nice talks about charge transport through molecules. Besides me, there were: Heiko Weber talking about his break junction systems; Latha Venkataraman talking about her break junction systems; Mark Ratner talking about charge transport in DNA; Nicolas Agrait talking about transport through 1d chains of Au atoms; and Philip Kim talking about graphene and nanotubes.
  • Mark Reed showed some interesting results on top-down fabrication and surface functionalization of Si nanowires for integrated sensors.
  • Eli Yablonovitch had some thought-provoking points about nanoelectronics and what we should all really be working on. I told him I wouldn't blog about this until he got it written up, so you'll hear more about this from me once it shows up on the arxiv.
Overall a very good meeting, though I regret not bringing hiking boots or having enough time to go skiing in the gorgeous Canadian Rockies.

Tuesday, November 07, 2006

A primer on faculty searches

It's been suggested that it would be valuable for me to post a brief description of the faculty search process. An obvious disclaimer: this is based on my experience, and may not generalize well to other departments with vastly differing cultures or circumstances. Anyway, here are the main steps in a search:
  1. The search gets authorized. This is a big step - it determines what the position is, exactly: junior vs. junior or senior; a new faculty line vs. a replacement vs. a bridging position (i.e. we'll hire now, and when X retires in three years, we won't look for a replacement then).
  2. The search committee gets put together. In my dept., the chair asks people to serve. If the search is in condensed matter, for example, there will be several condensed matter people on the committee, as well as representation from the other major groups in the department, and one knowledgeable person from outside the department (in chemistry or ECE, for example). The chairperson or chairpeople of the committee meet with the committee or at least those in the focus area, and come up with draft text for the ad.
  3. The ad gets placed, and canvassing begins of lots of people who might know promising candidates. A special effort is made to make sure that all qualified women and underrepresented minority candidates know about the position and are asked to apply (the APS has mailing lists to help with this, and direct recommendations are always appreciated). Generally, the ad really does list what the department is interested in. It's a huge waste of everyone's time to have an ad that draws a large number of inappropriate (i.e. don't fit the dept.'s needs) applicants. The exception to this is the generic ad typically placed by MIT and Berkeley: "We are looking for smart folks. Doing good stuff. In some area." They run the same ad every year, trolling for talent. They seem to do ok. The other exception is when a university already knows who they want to get for a senior position, and writes an ad so narrow that only one person is really qualified. I've never seen this personally, but I've heard anecdotes.
  4. In the meantime, a search plan is formulated and approved by the dean. The plan details how the search will work, what the timeline is, etc. A couple of people on the search committee will be particularly in charge of oversight on affirmative action/equal opportunity issues.
  5. The dean meets with the committee and we go over the plan, including a refresher for everyone on what is or is not appropriate for discussion in an interview (for an obvious example, you can't ask about someone's religion.).
  6. Applications come in and are sorted; rec letters are collated. Each candidate has a folder.
  7. The committee begins to review the applications. Generally the members of the committee who are from the target discipline do a first pass, to at least wean out the inevitable applications from people who are not qualified according to the ad (i.e. no PhD; senior people wanting a senior position even though the ad is explicitly for a junior slot; people with research interests or expertise in the wrong area). Applications are roughly rated by everyone into a top, middle, and bottom category. Each committee member comes up with their own ratings, so there is naturally some variability from person to person. Some people are "harsh graders". Some value high impact publications more than numbers of papers. Others place more of an emphasis on the research plan, the teaching statement, or the rec letters. Yes, people do value the teaching statement - we wouldn't waste everyone's time with it if we didn't care. Interestingly, often (not always) the people who are the strongest researchers also have very good ideas and actually care about teaching. This shouldn't be that surprising. As a friend of mine at a large state school once half-joked to me: 15% of the faculty in any department do the best research; 15% do the best teaching; 15% do the most service and committee work; and it's often the same 15%.
  8. Once all the folders have been reviewed and rated, a relatively short list (say 20-25 or so out of 120 applications) is arrived at, and the committee meets to hash that down to, in the end, five or so to invite for interviews. In my experience, this happens by consensus, with the target discipline members having a bit more sway in practice since they know the area and can appreciate subtleties - the feasibility and originality of the proposed research, the calibration of the letter writers (are they first-rate folks? Do they always claim every candidate is the best postdoc they've ever seen?). I'm not kidding about consensus; I can't recall a case where there really was a big, hard argument within the committee. I know I've been lucky in this respect, and that other institutions can be much more fiesty. The best, meaning most useful, letters, by the way, are the ones who say things like "This candidate is very much like CCC and DDD were at this stage in their careers." Real comparisons like that are much more helpful than "The candidate is bright, creative, and a good communicator." Regarding research plans, the best ones (for me, anyway) give a good sense of near-term plans, medium-term ideas, and the long-term big picture, all while being relatively brief and written so that a general committee member can understand much of it (why the work is important, what is new) without being an expert in the target field. It's also good to know that, at least at my university, if we come across an applicant that doesn't really fit our needs, but meshes well with an open search in another department, we send over the file. This, like the consensus stuff above, is a benefit of good, nonpathological communication within the department and between departments.

  9. That's pretty much it up to the interview stage. No big secrets. No automated ranking schemes based exclusively on h numbers or citation counts.

Monday, November 06, 2006

Ahhh, Texas.

While I generally enjoy living here, there are times when I really, really don't like living in Texas. For example, earlier today our governor (who is almost certainly going to be re-elected tomorrow, since the opposition to him will be split three ways, or four if you count the libertarian candidate) made me feel extra welcome. From the Dallas Morning News:

Gov. Rick Perry, after a God and country sermon attended by dozens of political candidates Sunday, said that he agreed with the minister that non-Christians will be condemned to hell.

Great. Why did the governor feel the need to talk about this at all? Apparently he feels that he needs to say things like that to get re-elected by my fellow Texas residents. Unsurprisingly, one of his opponents had a bon mot about this that I think says it all:

"He doesn't think very differently from the Taliban, does he?" independent Kinky Friedman said.