Chemistry Blog

Breaking Stuff for Science

Most chemists will agree, a chemical spill on the floor is one of the most annoying things to have to deal with in a lab. With LBL policy, you have to adhere to the SWIMS protocol: Stop work, Warn others, Isolate the area, Monitor yourself, Stay in the area. Not to mention using the correct spill kit, dealing with all the paperwork of the spill and the opening of the spill kit, explaining to the safety people what happened and why (hopefully) it wasn’t your fault, etc.

Aside from making sure your people are competent and well trained, not much is often done to prevent spills. Engineering controls such as secondary containment, fume hoods, capped reagent bottles, etc. work well when people remember and plan to use them. All too often, we see good chemists forgo extra safety steps for speed or just plain old laziness. Sometimes, people get badly hurt not because they were bad chemists or bad scientists, but because they really needed to catch the 6:40 train that day.

What we need are more safety devices that prevent the accident caused by a failure of the preventative safety measures from being very dangerous. For example, take these safety-coated reagent bottles from VWR. They have some plastic coating (PVC I think) outside of the glass to prevent spills even if the glass shatters. Sure some solvents would eat through the coating, but it would still buy you time to contain the spill, or evacuate the room if necessary.

Recently, with LBL’s current safety kick, our lab ordered 40 of these babies to replace our older reagent bottles. Interestingly though, the coating is really hard to see. In fact, when we first examined the bottles there was a dispute between some lab members as to whether we received the correct shipment or not.

Here is how the bottle looked, next to a typical graduate student size scale:

Being scientists however, Mitch and I knew that we couldn’t just take VWR’s word that we now had safety-coated reagent bottles.  We needed to test whether it really had the safety-coating, whether the coating would actually stay intact after an impact strong enough to break the glass inside, and whether the coating would feel weird if we poked with our finger.







So, using my safety training, I put the reagent bottle into a plastic bag, and put the plastic bag inside a phototray. Note the secondary and tertiary containment.






I went and found a big wrench, donned my safety goggles, lab coat, nitrile gloves and put the soon to be destroyed bottle durability testing apparatus into a fume hood with the sash half open.  I then proceeded to smash it to pieces. It was a good day of science.

Here is the result after a good beating. The safety-coating is quite clearly visible now, along with the area where the hole would be, if the coating wasn’t still covering it. The interior glass shattered as expected, but the safety-coating simply flexed a bit and recovered. Also, no sharp pieces of glass pierced the coating, so the contents of the bottle would have been contained. It took a significant amount of effort with some sharp tweezers to illustrate the intact film of the coating. We also confirmed our hypothesis that poking the film with our finger would feel weird. The bottle met our expectations in all tested categories. It also looked really cool and took a great picture.

So in our effort to make the lab safer, we tested and confirmed the usefulness of these safety-coated reagent bottles in an easily repeatable scientific experiment. Tests would have been done in triplicate, however funding was abruptly cut off when we attempted to share our findings with others in the lab.  We recommend the safety-coated bottles for use throughout the chemistry lab. All waste was disposed of in coordinance with EH&S protocol.

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Teen Chemist and Splenda

For as long as artificial sweeteners have been used, there has been a varying level of controversy over the safety of their use; both for humans and the environment in general. Saccharin and Aspartame have been plagued by health concerns raised by researchers for decades. Most studies have shown that only in very high concentrations are they dangerous, however few long term (>10 years) studies have been completed, so lower dose, chronic exposure has yet to be rigorously  investigated. Currently, most diet sodas use aspartame and saccharin, including my favorite, Coke Zero. Another very popular sugar substitute, sucralose has begun to steal the spotlight away from aspartame in recent years, taking over popular drinks like Crystal Light, Tim Horton’s and Starbucks coffee.

The chlorinated sugar substitute called sucralose (commercially marketed as Splenda (TM)) was first synthesized in 1976, as part of a collaboration between Queen Elizabeth College in London and the Tate and Lyle Chemical Company. It is manufactured by the selective chlorination of sucrose, in which three of the hydroxyl groups are replaced with chlorine atoms. Supposedly the graduate student, Shashikant Phadnis, working on the synthesis misunderstood his professor’s request to test the chemical as a request to taste the chemical. Just goes to show, sometimes to make a lucrative discovery, a chemist must take the ultimate test!

Whatever happened, it has been found that Sucralose is approximately 600 times sweeter than sucrose, and since being introduced in the USA in 1998, has become one of the leading sweeteners on the market. One of the main reasons for this is that studies have shown that sucralose is highly stable; it doesn’t break down easily due to heat so cooking with it is safe. It also doesn’t dechlorinate over time, photo degrade under visible light, or biodegrade with common bacteria. It is also very insoluble in fat cells, so all of us Americans don’t have to worry about getting a heart attack on the treadmill (at least not from sucralose!). In fact, sucralose is so darn stable, it doesn’t even get broken down in waste treatment plants.

Meet Smitha Ramakrishna, a senior at Corona del Sol High School in Chandler, Arizona, who has been doing research at Arizona State University about sucralose’s inability to be broken down and how this make affect the environment. At only 17 years of age, she has been researching sucralose for nearly 2 years, as part of her greater goal of trying to help with global water issues. She also founded an organization named AWAKE, which is dedicated to increasing her community’s awareness about water-related issues.

She has found that after subjecting sucralose to treatments similar to those used by waste water treatment plants, the sweetener resisted bacterial digestion. Only after a long time and under UV irradiation in the presence of high concentrations of titanium oxide (TiO2) did the sugar break down. Considering that few plants use these methods, the majority of sucralose in wastewater enters the ecosystem. She doesn’t say for sure what effect this will have, but says that preliminary studies suggest high concentrations of sucralose may poison fish.

See more here: That Splenda you’re drinking will be in our water supply for a while

Personally, I think people should use xylitol more. First studied in the 1970’s, almost no negative effects have been found due to ingestion of even 400+ grams a day (imagine 400+ grams of sugar! BLECH!) and many positive health effects have been proven ranging from plaque-reducing effects to boosting your immune system. It is about as sweet as sucrose, and has 2/3 the caloric content.

That said, I am still gonna go get me a coke zero.

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Light Powered Motor and Experiment Vlogging

Most of you probably read the last issue of C&EN with the spiffy carrot loving cover story (good for me because I love carrots, but have never tried those ugly-looking BetaSweets). Inside, however, there was an extremely interesting little article in the “Science and Technology Concentrates” about light-driven pulleys turning a plastic motor.

Now photo mobile polymer materials have been around for quite a while, at least from my perspective seeing as how I wasn’t even in highschool when the big Nature paper came out. Some might remember the Nature 1999 Sep 9;401(6749):152-5 Koumura et al. paper titled “Light-Driven monodirectional molecular rotor”. Although back then, the rotation was monodirectional around a C-C double bond in a chiral, helical alkene. It was activated by UV light or a change in temperature and the motor was based on light-induced cis-trans isomerizations that caused 180 degree rotations followed by thermally controlled helicity inversions, which basically nullified half a rotation. Four isomerizations resulted in 1 complete cycle.

Well this was pretty darn cool but we’ve come a long way since then. As expected, and as Koumura said, structurally modified chiral alkenes played the central role in the development of these molecular motors that were beginning to interest the MEMS people (MEMS stands for Micro-Electromechanical Systems…I am pretty sure).

In J Am Chem Soc. 2003 Dec 10;125(49):15076-86, ter Wiel MK et al. introduced the worlds smallest artificial light-driven motor using 28 carbon atoms and 24 hydrogen atoms.

Reprinted with permission from American Chemical Society: Journal of the American Chemical Society (Nov. 2003).

It also had a dramatic speed increase over the original designs, at a whopping 18s half-life at the fastest step. Even if it wasn’t going to be turning any relevant loads any time soon, it was a dramatic improvement over the original concept 4 years earlier. Still, even though some clever O-chem tricks made the motor better, it still operated on the same 4-step cycle that Koumura’s did back in 99′. Even recently, in Org. Biomol. Chem., 2008, 6, 507 – 512, DOI: 10.1039/b715652a, Pollard et al. report on substituting naphthalene moieties for phenyl moieties, in order to better control the speed of the motors, and to enable the design and synthesis of more complex systems.

Meanwhile, the MEMS people came up with interesting designs similar to this:

“A five micron wide resin structure, with a shape resembling a lawn sprinkler, rotates when illuminated by a laser beam. Tiny rotors like this one may someday power micromechanical systems (MEMS), or twist molecules to measure their mechanical properties.” Reported by: Péter Galajda; Pál Ormos, Applied Physics Letters, 8 January, 2001.

There was quite a bit of work done focusing on creating rotors that responded to laser light, although the practical applications of such devices aren’t as numerous as the devices that…well don’t require a coherent, collimated, polarized light beam to operate. Or at least they weren’t until Peidong Yang’s came around with his nanolasers.

Unfortunately, all of these motors share the drawback of being unidirectional. It was until recently, with Ikeda’s et al. paper in Angew. Chem. Int. Ed. 2008, 47, 4986, that a very cool and new method for directly converting light into mechanical work. Basically they drew on the fact that azobenzene derivatives, when incorporated into liquid crystals, can have an isotropic phase transition induced isothermally by irradiation with UV light to cause trans–cis photoisomerization, and that the reverse transition can be induced by irratiation with visible light to cause cis-trans back-isomerization. This photoinduced phase transition
led to successfully reversible deformations of liquid crystal elastomers containing azobenzene chromophores just by changing the wavelength of the incident light.

Now this by itself doesn’t a motor make. There was one large problem: the liquid crystal elastomer had to be made into a film or “belt” for a motor. However, the LCE film by itself wasn’t mechanically strong enough and tended to crack after short light irradiation at high intensities. So to fix this issue, they simply laminated the LCE film with flexible polyethylene sheets. I love this type of simple solution to what could have been a convoluted problem. This is very much like what Mitch and I tend to do.

*Note that they did do a study of increasing light intensity and it’s correlation to the mechanical force generated by the film. They found that “the maximum force and the increment rate of the generated force are enhanced with an increase of the light intensity.”*

So what happened? Well check this out:

Thats right. That is an actual light-driven motor NOT on the micro-scale. The diameter of those pulleys are 10mm on the left and 3 mm on the right. Sure it isn’t going to be competing in any races at the moment, but it could still be amazingly useful in the future. Light, straight to DC? That would be pretty darn awesome.

PS. Tomorrow is the first day of the experiment Mitch and I are running. Since we can, we will be broadcasting the first live cyclotron experiment out over the interweb. This may be one of the first live nuclear physics experiments broadcasted. Other then that, it is just cool. SO we will have it up all 24 hours as a “live vlog”.

Feel free; hell feel obligated to stop by, leave a comment, chat, ask questions, offer constructive or destructive criticism, whatever. Maybe ACS will pick this up as a new way to present new research: present it as it happens! Live!!!

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Wanted (the movie)

So I know that this doesn’t qualify as a chemistry post, but it’s still pretty darn cool.

Earlier today, Mitch scored some free pre-screening tickets for a movie called Wanted with Angelina Jolie in it.  There was some white guy in it too, as the main character, but I didn’t really know or care who he was.  In fact, I had no idea what the movie was about until we went and saw it.  When Mitch told me that Angelina Jolie was in it, I accepted the invitation.

So he got the tickets through Techcrunch, a blog that focuses on reviewing new tech. products (mostly internet products) and companies.  It was a first come first serve sort of contest and Mitch happened to log onto their website just it was posted.  He got two tickets, and we drove out to the Metreon theater San Francisco.

We get there and get in line, and find out that there are about 250-300 ppl coming to see this prescreening.  Many people got their tickets through techcrunch, allowing us that always sweet line cut since they had a separate ticket check system.  The Myspace ppl, on the other hand, were stuck in line, cursing us as we went past.  I think I forgot to mention that the event was cosponsored by techcrunch and Myspace.

Seeing a movie in a prescreening is pretty darn cool.  It was kinda like going to see a movie at the opening show.  The whole crowd gets into it and sort of participates in the movie.  Apparently there is a sort of “movie prescreen” subculture as evidenced by the fact that many of the movie goers knew each other from other prescreens and were discussing the latest events; some bemoaning their inability to secure Wally prescreen tickets.

Anyways, the movie itself was really freaking cool.  It is a super action, fast-paced thriller i guess with some cheese, cool music, and a light attitude.  It wasn’t all serious, which would have totally ruined the movie.  Both Mitch and I were amazed to find ourselves actually liking the movie a lot, and I see it becoming a total guy movie-night classic.

Also cool, was that I came home and watched the daily show only to find James McAvoy (the name of the main character) as the guest.  Apparently he has heavy scottish accent that.  During the movie though, I had no idea that he wasn’t American.  I guess he is a pretty good actor.

So yeah, that’s my movie pitch.  After seeing one of the most entertaining, if not really interesting, movies I have seen in a looong time, I had to go and blabber about it.  Another bonus was of course seeing Angelina Jolie looking oh-so gorgeous again.

Heh, and I saw a lot of other ppl blogging or talking about blogging about it, so I had to add my two cents.

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From ACS New Orleans

Hey there, from New Orleans! ACS 2008 kicked off today with the early morning registration rush that is required for every ACS meeting. This one, however, was awesomely bad, as the organizers, displaying true ig-nobel prize worthy genius, nearly caused an uprising from the mob of chemists waiting for their ID-cards.

So here’s what happened. Around 8 in the morning, chemists of all sorts spilled into the registration hall at the convention center in the French quarter of New Orleans. To register for the conference, each person had to first enter their information into the onsite computers, pay a fee, and then go collect the printed out ID cards. The first part of this procedure went fine, and it took only minutes for myself, Mitch, and Noel to pay the registration fee and get in line for the ID card. However, the wait for picking up the admission badge is where everything went haywire.

Instead of intelligently placing the printers next to the ID card readers so that new registrees could grab their papers and assemble their own ID’s, the organizers decided to have 3 printing stations where the ACS hosts would carefully complete the complicated task of folding the papers in half, inserting them into a plastic holder, and lacing an ACS lanyard through the tag.

One particularly loud lady, the “supervisor” – we were told so by other employees who refused to accept responsibility of the brewing crisis- especially endeared herself to the crowd. After waiting 20 minutes or more to reach the front of said printing line, the self-proclaimed “lady in red” was…well, let me paint the picture for you.

Imagine yourself, after waiting for what has felt like hours of standing in a much too long line, checking your watch every few minutes because your chance to hear about element 108 and the plans to make 120 is literally ticking away. Finally you begin to reach the front of the line: you can hear names being called and briefly think about how nice it would be to get your tag. But wait…something is wrong. You hear people’s names called, followed by groans, moans and subdued protests. Thats not right…you think to yourself. Then you hear the words that make you hope…no pray, that this little “lady in red” does not call your name.

“John Blahblah!”

“Yeah, here!”

“Sir, Back of the line please!”

“WHAT?!?!?!?!”

“Sir, Back Of The Line.”

And there it is. The bottle-neck in the registration process that eventually led to this:

was caused by the assumption that chemists can’t make their own nametags. Yes, the above picture is Mitch becoming an honorary ACS crowd manager as he hands out the plastic ID card holders to near-unruly chemists. Although, I probably didn’t help the situation by loudly telling people not to budge if told to move to the back of the line. What can I say…I am just a rebel.

So Kudos to the ACS event organizers. The first few hours of the first day of the conference was a complete hash, a prime example of how NOT to manage a huge national conference’s registration. For all those unfortunate chemists who missed the morning talks, or decided to forgo the idiotic ID to actually attend those talks, or were just generally upset by the morning’s administrative malfunctions, I hope you comment on this post. Or just comment if you find it funny. Or if you want to make fun of me. Whatever.

-Maz

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IG Nobel Prizes

So after the Physics Nobel Prize Post, I felt it would be necessary to point these out as well. For those of you who don’t know what the IG Nobel Prizes are…well, I think you’ll figure it out.

Oh, one last thing. These are all awarded by The Annals of Improbable Research, which is an institution like (heh, sort-of) The Royal Swedish Academy of Sciences which awards the Chemistry and Physics Nobels, or the The Norwegian Nobel Institute which awards the Peace Nobel.

Here we go:

MEDICINE:
Brian Witcombe of Gloucester, UK, and Dan Meyer of Antioch, Tennessee, USA, for their penetrating medical report “Sword Swallowing and Its Side Effects.”
REFERENCE: “Sword Swallowing and Its Side Effects,” Brian Witcombe and Dan Meyer, British Medical Journal, December 23, 2006, vol. 333, pp. 1285-7.
WHO ATTENDED THE CEREMONY: Brian Witcombe and Dan Meyer

PHYSICS:
L. Mahadevan of Harvard University, USA, and Enrique Cerda Villablanca of Universidad de Santiago de Chile, for studying how sheets become wrinkled.
REFERENCES:”Wrinkling of an Elastic Sheet Under Tension,” E. Cerda, K. Ravi-Chandar, L. Mahadevan, Nature, vol. 419, October 10, 2002, pp. 579-80.
“Geometry and Physics of Wrinkling,” E. Cerda and L. Mahadevan, Physical Review Letters, fol. 90, no. 7, February 21, 2003, pp. 074302/1-4.
“Elements of Draping,” E. Cerda, L. Mahadevan and J. Passini, Proceedings of the National Academy of Sciences, vol. 101, no. 7, 2004, pp. 1806-10.
WHO ATTENDED THE CEREMONY: Lakshminarayanan Mahadevan, and Enrique Cerda Villablanca’s sister Mariela.

BIOLOGY:
Prof. Dr. Johanna E.M.H. van Bronswijk of Eindhoven University of Technology, The Netherlands, for doing a census of all the mites, insects, spiders, pseudoscorpions, crustaceans, bacteria, algae, ferns and fungi with whom we share our beds each night.
REFERENCES: “Huis, Bed en Beestjes” [House, Bed and Bugs], J.E.M.H. van Bronswijk, Nederlands Tijdschrift voor Geneeskunde, vol. 116, no. 20, May 13, 1972, pp. 825-31.
“Het Stof, de Mijten en het Bed” [Dust, Mites and Bedding]. J.E.M.H. van Bronswijk Vakblad voor Biologen, vol. 53, no. 2, 1973, pp. 22-5.
“Autotrophic Organisms in Mattress Dust in the Netherlands,” B. van de Lustgraaf, J.H.H.M. Klerkx, J.E.M.H. van Bronswijk, Acta Botanica Neerlandica, vol. 27, no. 2, 1978, pp 125-8.
“A Bed Ecosystem,” J.E.M.H. van Bronswijk, Lecture Abstracts — 1st Benelux Congress of Zoology, Leuven, November 4-5, 1994, p. 36.
WHO ATTENDED THE CEREMONY: Dr. Johanna E.M.H. van Bronswijk

CHEMISTRY:
Mayu Yamamoto of the International Medical Center of Japan, for developing a way to extract vanillin — vanilla fragrance and flavoring — from cow dung.
REFERENCE: “Novel Production Method for Plant Polyphenol from Livestock Excrement Using Subcritical Water Reaction,” Mayu Yamamoto, International Medical Center of Japan.
WHO ATTENDED THE CEREMONY: Mayu Yamamoto
PRESS NOTE: Toscanini’s Ice Cream, the finest ice cream shop in Cambridge, Massachusetts, created a new ice cream flavor in honor of Mayu Yamamoto, and introduced it at the Ig Nobel ceremony. The flavor is called “Yum-a-Moto Vanilla Twist.”

LINGUISTICS:
Juan Manuel Toro, Josep B. Trobalon and Nuria Sebastian-Galles of Universitat de Barcelona, for showing that rats sometimes cannot tell the difference between a person speaking Japanese backwards and a person speaking Dutch backwards.
REFERENCE: “Effects of Backward Speech and Speaker Variability in Language Discrimination by Rats,” Juan M. Toro, Josep B. Trobalon and Nuria Sebastian-Galles, Journal of Experimental Psychology: Animal Behavior Processes, vol. 31, no. 1, January 2005, pp 95-100.
WHO ATTENDED THE CEREMONY: The winners could not travel to the ceremony, so they instead delivered their acceptance speech via recorded video

LITERATURE:
of Blaxland, Blue Mountains, Australia, for her study of the word “the” — and of the many ways it causes problems for anyone who tries to put things into alphabetical order.
REFERENCE: “The Definite Article: Acknowledging ‘The’ in Index Entries,” Glenda Browne, The Indexer, vol. 22, no. 3 April 2001, pp. 119-22.
WHO ATTENDED THE CEREMONY: Glenda Browne

NUTRITION:
Brian Wansink of Cornell University, for exploring the seemingly boundless appetites of human beings, by feeding them with a self-refilling, bottomless bowl of soup.
REFERENCE: “Bottomless Bowls: Why Visual Cues of Portion Size May Influence Intake,” Brian Wansink, James E. Painter and Jill North, Obesity Research, vol. 13, no. 1, January 2005, pp. 93-100.
Mindless Eating: Why We Eat More Than We Think, Brian Wansink, Bantom Books, 2006, ISBN 0553804340.
WHO ATTENDED THE CEREMONY: Brian Wansink.

ECONOMICS:
Kuo Cheng Hsieh, of Taichung, Taiwan, for patenting a device, in the year 2001, that catches bank robbers by dropping a net over them.
REFERENCE: U.S. patent #6,219,959, granted on April 24, 2001, for a “net trapping system for capturing a robber immediately.”

If that crap can get patented…Mitch, I think we need to revist that patent.

AVIATION:
Patricia V. Agostino, Santiago A. Plano and Diego A. Golombek of Universidad Nacional de Quilmes, Argentina, for their discovery that Viagra aids jetlag recovery in hamsters.
REFERENCE: “Sildenafil Accelerates Reentrainment of Circadian Rhythms After Advancing Light Schedules,” Patricia V. Agostino, Santiago A. Plano and Diego A. Golombek, Proceedings of the National Academy of Sciences, vol. 104, no. 23, June 5 2007, pp. 9834-9. WHO ATTENDED THE CEREMONY: Diego A. Golombek

And My Personal Favourite (remember, this is for the PEACE prize):

PEACE:
The Air Force Wright Laboratory, Dayton, Ohio, USA, for instigating research & development on a chemical weapon — the so-called “gay bomb” — that will make enemy soldiers become sexually irresistible to each other.
REFERENCE: “Harassing, Annoying, and ‘Bad Guy’ Identifying Chemicals,” Wright Laboratory, WL/FIVR, Wright Patterson Air Force Base, Ohio, June 1, 1994.

So take off your hats and raise your glasses to these brave and ignobel scientists, wasting our hard won funding, and pushing the very edge of our understanding of useless crap. Cheers.

Maz

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GMR and the Nobel Prize

A computer hard disk reader that uses a GMR sensor is equivalent to a jet flying at a speed of 30,000 kilometers (19,500 miles) per hour … at a height of just one meter above the ground, and yet being able to see and catalogue every single blade of grass it passes over,” [Ben Murdin, a physics professor at the University of Surrey in southeast England] said.

Impressive, eh?  This year’s Nobel in physics was awarded for something that you actually use on a daily basis…but never think about. Albert Fert and Peter Grünberg get to split $1.5Million for their discovery of Giant Magnetoresistance (GMR).  I know; not only does it sound amazingly cool, but it’s actually useful?  I mean, anti-particles, darkmatter, parallel universes and string theory are sexy and all, but come on.  This tech. actually is called Giant.  Not to mention that the discovery of GMR led to the field of spintronics, and the principles behind your iPod and 500 gigabyte hard drive.

On to the science.

To start this discussion, I have to explain a little about spin and it’s interaction with mag. fields.
NOTE:  SKIP THIS SECTION IF YOU ALREADY KNOW THE BASIC BACKGROUND

Let’s review.

So if you sent a beam of electrons through a magnetic field and had some quantum trash bags to collect the electrons upon exiting this mag. field, you’d see that 1 bag was full of spin up electrons, and 1 bag was full of spin down electrons.

One way you can attempt to rationalize this (and I know this is a little hand-wavy, but it’ll do) is to imagine an infinitesimal charge, dq on the surface of the electron.  If we see that the electron is spherical and spinning, either clockwise or counterclockwise, then this dq rotates about as well.  So would all the other dq’s on the surface of the electron.  You know that the flow of charge generates a magnetic field.  Through Maxwell’s eq. you could show that if the electron is spinning clockwise it’s z-axis, you’d see a magnetic field pointing in the “-z direction” (remember, no magnetic monopoles (we think) so the field lines could be thought of as initially going out the bottom of the electron. and then curling back up to arrive at the top), and if it was spinning counterclockwise, you’d see the field pointing in the +z direction.  These two dipole moments we call spin up and spin down, and they either align in parallel with the external magnetic field, or antiparallel with it.  As you’re probably guessing, the parallel alignment is slightly lower in energy then the antiparallel.  This is known as the Zeeman effect.

END REVIEW

So GMR is, in my opinion, one really big and really cool trick.  I say so because it’s one of those things that seems to me as obvious but not trivial.  There are a few different types of GMR applications that operate off of the same basic principle.  Here I’ll talk about the most used one, the spin-valve.

If you take a ferromagnetic layer and polarize it, the unpaired electrons in the layer will align themselves to the external magnetic field.  These electrons are now what we call “spin polarized”.  Do this for a second layer and place them next to each other, but separated by a non ferromagnetic layer.  Slap a potential difference across the two layers, and the electrons will maintain their polarization while moving through the circuit.  But when these electrons hit a material with a mag. field opposite their spin direction, they get flipped.  And here’s the rub:  flipping the spins requires extra energy…in other words the electrical resistance is increased when the magnetic materials are polarized in the opposite directions (anti-parallel alignment).

Who cares?  Well, you do, you just might not see it yet.  Being able to change the like this electrical resistance, which is easily detectable, is what computer guys call “non-volatile”.  Meaning you don’t require power to keep the changes made.  If you let the “low resistance” represent 1 and the “high resistance” represent 0, you can get digital logic.  Imagine doing what we just discussed, hundreds of billions of times on a 3.5″ disc…and you’ve got yourself a hard drive.  This is a relatively simple type of spintronic device, which is why they say that the GMR discovery gave birth to the field of spintronics.

Spintronics is, in general, the development of technology which allows you to make use of the spins of electrons. If you can generate a current of like-spinned electrons, i.e. polarized electrons, and send them through a device that can detect and act based on the spin of these electrons, you have created a spintronic device.  It is sensitive not to voltage or charge or mass, but on the electron’s spin.  That’s a really big deal.  After-all, you’ve got an intrinsic 1 or 0 right there.

So the next time you strap that overpriced, little white noise machine onto your arm and go for a jog, say thanks to a couple of physicists who discovered something that turned out to be useful…in your lifetime.

Note:  This was by no means a rigorous discussion, and if anyone is interested in the topic, you could start a thread in the forums and see what grows.  For the blog though, this is maybe already too indepth.  I should have added some pretty pictures. 

Maz

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Energy Discussions 1: Water Cars

Since I have seen a number a of energy related topics on the boards in the past few weeks and Mitch decided to talk about cold fusion, I decided my next few posts will be related to new/renewable energy alternatives to fossil fuels.

This particular post was inspired by the many, many electrochem. questions by Walman who also reminded me about Stanley Meyers’ work on water cars.

Yes thats right…water powered vehicles.

Now I know you are all rolling your eyes saying things like “electrolysis takes about 5 times more energy in then you get out” or “If he really invented some new form of electrolysis why don’t we all drive water cars?” and of course “Who cares? Maz is nuts anyways!”.

I would ask you naysayers to wait a bit and take a look at some of this guy’s evidence. NOTE: I don’t really buy it, but you never know. It may be possible.

So lets begin with a basic review of electrolysis, which is the separation of certain bonded atoms or molecules by running electric current across them. We are concerned here with the electrolysis of water which goes like this:

2H₂O –> 2H₂ + O₂ Where the H₂O was in liquid phase, and the hydrogen and oxygen products are in gas phase.

When you put enough electrical current across water, you add enough energy for the water to split into its ionic components. Hydrogen, being positively charged, moves toward the cathode and oxygen, being negatively charged, moves toward the anode. When hydrogen cations hit the cathode, they get reduced and form H₂ gas. Oxygen hits the anode and gets oxidized, forming O₂ gas.

Now the quantity of the separation is proportional to the amount of electric charge you send across. This means that the more current you send through, the more hydrogen gas you get (within limits of course). So we can all have electrolytic cells producing hydrogen to burn for our cars and homes, right? Well…not exactly. The amount of energy you get out from burning the products of the electrolysis is not greater then the amount of energy it takes to do the separation. Classical theory predicts the maximum efficiency to be between 80 and 94% See here for details

This key point is where Stanley Meyers claimed to make a breakthrough. Using his own design of an electrolytic cell, he said he gets somewhere around 1700% efficiency.

His design for the cell is different from contemporary cells in that they utilize tiny amounts of current. Half an amp, for his 1700% efficient design. The trick, it seems, is to use high voltages with low current and PULSE the current using large surface area electrodes.

Why does this supposedly work? You’ve got me there. Perhaps there’s some weird interaction driven by the strong force at the electrodes? Maybe you cold fusion enthusiasts ought to look into it with high pressure confinement. Maybe then you’ll see your fusion.

Whatever the case, and whatever your current opinion is, first watch these two videos. The first is just 2 minutes long, the second is a more serious 17 minute clip. THEN formulate your opinion. Of course I would also say you should visit the wikipedia article on Stanley Meyer

Video 1: http://www.youtube.com/watch?v=YIgOn1kRw5s

Video 2: http://video.google.com/videoplay?docid=-3333992194168790800

Obviously, I think that his ‘water fuel cell’ is pretty much a vat of crock. I am sure it is a conspiracy theorists dreamland, but then again, all the supposed “free energy” inventions are.

Except for mine of course. But that’s a secret.

P.S. If anyone reading this understands Japanese, could you please tell me what they are saying in this video?

-Maz

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