By Christopher Moore
A proposal that a few colleagues and I submitted to the National Science Foundation (NSF) has been recommended for funding by the Division of Materials Research. One of the PIs on the grant is my former dissertation adviser and some of the proposed work involves using a novel combination of techniques that I developed in my dissertation.
I would be doing the work during the summer months anyway, but it sure is nice to be getting paid for it. Plus, I’ll have money to pay undergrads to work in my lab and travel to conferences.
My former adviser is getting concerned about my recent charmed professional life: I apply for tenure-track jobs straight out of grad school (no post-doc experience, which is unusual) and I get three offers the first year. Now, the first NSF proposal I submit gets funded. Maybe I should go ahead and submit a CAREER proposal. CAREER grants are highly competitive NSF grants for young scientists. After the almost certain failure to get past the referees for that program, then I can come back down to Earth. 
By Christopher Moore
Donnie and I have finally managed to get a stable tunneling current with our STM. On Thursday we ran a couple of traces in the x-direction, and as long as we didn’t touch the table or the air handler wasn’t on we saw minimal historesis.
Next week we will set everything up on stone block/foam sandwiches for vibration isolation, put in a gold sample, and try to get a decent XY scan on the oscilloscope. I’ll post pictures then.
By Christopher Moore
My wife is watching “Dancing with the Stars”. I’m working; however, I am upset Penn Jillett was kicked off the show even though I’ve never actually seen him dance since I don’t normally pay much attention while my wife watches. His show “Bullsh@t” on Showtime is a terrific show for anyone interested in real science and the debunking of psuedo-science.
Anyway, I digress. The reason for this post is that the Jonas Brothers were playing on the show. I had never heard them before. Now I have heard them — twice in the last hour — and they are absolutely terrible. They are technically bad. Just awful.
[end pointless rant]
By Christopher Moore
The San Fransisco Chronicle reports that a Quaker math teacher was fired for refusing to sign an oath of allegiance. This is not necessarily physics news, but having gone to Guilford College and having a background in the Society of Friends, this is an interesting story to me.
Marianne Kearney-Brown, a Quaker and graduate student who began teaching remedial math to undergrads Jan. 7, lost her $700-a-month part-time job after refusing to sign an 87-word Oath of Allegiance to the Constitution that the state requires of elected officials and public employees.
You see, Ms. Kearney-Brown did the following each time the oath was presented to her:
Each time, when asked to “swear (or affirm)” that she would “support and defend” the U.S. and state Constitutions “against all enemies, foreign and domestic,” Kearney-Brown inserted revisions: She wrote “nonviolently” in front of the word “support,” crossed out “swear,” and circled “affirm.” All were to conform with her Quaker beliefs, she said.
She refused to sign the statement unaltered, and she was fired.
You see, Quakers have this little hang-up on non-violence. It’s nothing big, really, it’s just sort of one of the foundations of the religion. The oath as written is like asking a Hindu to swear to defend the constitution from all enemies, including cows. Also, the statement is vague. Very vague. What constitutes an enemy of the constitution? I claim that a large majority of our Representatives in Congress are “enemies” to the constitution. Who defines “enemies”? And what constitutes “defend”.
Ms. Kearney-Brown makes the following point:
All they care about is my name on an unaltered loyalty oath. They don’t care if I meant it, and it didn’t seem connected to the spirit of the oath. Nothing else mattered. My teaching didn’t matter. Nothing.
By Christopher Moore
My student and I are still working hard on our scanning tunneling microscope. We’ve had some issues with the solder-less breadboard we were using to prototype. Stuff was shorting on the breadboard, so we placed the components on a proto-board and soldered them together.
The pre-amp is now working exactly like it should. We supply a low current via a make-shift current source measured using a picoammeter and read correct voltage values on the other side. We’ve simulated the pre-amp using MultiSim and our circuit is behaving like the simulation.
The difference amplifier is another story! We’re still troubleshooting that, since it isn’t doing anything like what it should. With a +5 V signal and a set-point of +3 V, we should get a +2 V output. We get something different, though the something does scale correctly with variations in the set-point.
The scanner control electronics are working fine. They always have.
Over the next few weeks we expect to have all of the electronics properly placed on proto-boards, tested and functioning as they should. We have to go back and build a new approach mechanism for two reasons:
(1) The quasi-kinematic approach using machine screws is TERRIBLE! I have a micro-positioner thingy I salvaged from the junk heap that we plan on using for the fine approach. The coarse approach will still be made via machine screws. We’re also going to make the stage and lever much bigger. An STM that can fit in a pocket is no longer a goal — we’d rather have one that works!
(2) If you look back at the pictures of our piezo scanner, you’ll notice relatively large gauge wires and solder. I think the wires are too stiff, too thick and offer too much resistance. Also, it is possible that we’ve de-poled our piezo, though I’ve soldered piezo-electric ceramic before with fantastic results. We’re going to build the new scanner with smaller gauge wire and silver paste.
Concerning the piezo: I have a student using a Michelson interferometer to measure the piezo displacement with voltage for calibration purposes, and to convince myself that I haven’t de-poled the ceramic.
The department is purchasing licenses for LabVIEW and I have ordered some data acquisition boards. Once we’re done troubleshooting the STM via the oscilloscope, then the next student I can cajole into working on this project will be developing LabVIEW code to control the set-point, gains, and sample bias and pick-off the x,y,z voltages and convert them into pretty pictures. If we get really ambition, then maybe we’ll design an all digital feedback STM. That will require much faster DAQs, though, taking the project out of the couple-of-hundred-dollars range.
By Christopher Moore
I have been missing for a long time.
Last year I was busy writing and defending a dissertation. Then I got a new job. I’ve moved, had a baby and started a new career in the span of six months. Hopefully you understand my absence.
However, the long neglect of ilovephysics.com is officially over. I am starting a new column called “Ask a Physicsist.” Click on the graphic at the top of the page to learn more. Essentially, I’m going to start answering your emails! I get several a week from Physics Phans and crackpots and others, and I thought I would make my responses a little more … ummm … well … I’m actually going to start responding. However, I’m going to respond via this public forum so that everyone can benefit from my wisdom .
Also, two students will be coming on board as contributors to this site. I’m kind of forcing them to contribute, since I control their grade!
Donny will be blogging about the STM project that he is working on. And Andy will begin blogging about a vacuum sputtering system that he will be building this semester. Look for their contributions in the next week or so.
So I’m back. Let’s hope I’m better at finding time to write this semester.
By Christopher Moore
I am a scanning tunneling microscope (STM) guy. I completed my M.S. thesis using a commercial instrument and I have always wanted to build one. Until recently, I haven’t had the time or the money. About 1 month ago, a student here at Longwood University approached me about doing a project. The first thing that came to my mind was “Let’s build an STM!” The student agreed, and off we went. Now building an STM is part of my job!
Commercial research STM systems cost up to $250k or more. Less powerful “student” systems run around $15,000 but offer little to the researcher. The STM that my student Donald and I are building will end up costing ~$100 in parts. More important, the parts can be found at the local hardware store or ordered online.
Over the next few months Donald and I will chronicle the construction of our STM, showing you what parts we have used, how we are constructing it, and how it works. We plan to have a fully-functional analog STM up and running by the end of this semester (early December 2007). Next semester begining in January, we will chronicle the build of our second STM which will be digitally controlled via a computer. The budget for our computer controlled model is less than $200, and the microprocessor and control board are being designed by an undergraduate at Virginia Commonwealth University.
We have already begun. To learn more about STM, this specific project, or current progress, and what’s next, continue reading.
(more…)
By Christopher Moore
Here is an interesting article about biofuels posted at Functionalism In Action by Ian Conrad:
There is so much hype, today, about biofuels. They are seen as the savior of our nation — especially corn-ethanol; especially if one were to compare the subsidization that goes on here. But is this the right approach?
The article continues, making the following point with regards to a new process af turning corn sugar into good old fashioned gasoline:
To compare, the most effective gallon-per-acre biofuel crop right now is palm oil, which hovers around 680 gallons-per-acre. So this is more than triple the amount — and it’s good ol’ fashioned gasoline to boot! Here comes the number crunching. In 2004, the US used approximately 318 billion gallons of oil. At 2,000 gallons per acre, that comes out to roughly 159 million acres of arable land — and this is assuming that the cellulosic starch problem can be overcome — for which there are no hypothetical solutions yet available. According to the CIA’s “World Factbook”, the US has 9,161,923 square kilometers of land, 18.01% of which are arable. That’s 1,650,62 square kilometers. 1 acre = 0.00404685642 square kilometers, so the US has 407,739,281 acres of arable land. To maintain the energy usage levels of 2004 purely from biofuels derived from this process would require ~40% of all arable land in the nation.
The question Ian asks is an important one, considering a slew of would be presidents are busy interupting the breakfasts of Iowans: “What the devil is the justification of the subsidization of corn-ethanol production?”
Read the entire article here.
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