Wednesday, July 30, 2008

Getting Violent over Glass

The New York Times has a decent article on some of the latest research on the glassy state. It's more than the old does-glass-flow arguements and hints at some of the difficulties.

What I really liked is that it captures the intensity of the argument, or more properly, the people involved. Only twice in my life have I ever seen a technical argument get to the point where I thought fists would fly - both times have been over the glass transition. And I've heard similar experiences from others. So when the Times article states: 1)"Thirteen years later, scientists still disagree, with some vehemence, about the nature of glass." and 2)“Many people tell me this is very contentious. I disagree violently with them.” (emphasis added), I can tell the author got it right.

Tuesday, July 29, 2008

Chemical Obviousness in Patents

To receive a US patent, the "invention" must pass three tests: 1) usefulness, 2) novelty and 3) non-obviousness. The first is easy to pass, the 2nd can take more effort to determine (and the determination is always subject to later reviews) but is doable while the last is the most difficult due to this question: When is an invention obvious?" Attempts to define obviousness have been going on for over 200 years and are not settled.

The SCOTUS recently came down with a landmark decision in the area KSR v. Teleflex which concluded that if you take two or more mechanical parts and combine them in such a way that they do no more than the sum of the parts, the invention is obvious. i.e., 1 + 1 = 2 is obvious, 1 + 1 = 3 is not, ditto for 1 + 1 = 0. In the second (and third) case, you found an unexpected result. Prior to this, the standard for obviousness was that an invention was obvious ONLY if there was literature stating that you should combine 1 + 1 to get 2. If no one had said 1 + 1 = 2, it was considered non-obvious.

KSR however only applies to mechanical devices. A new appeals court decision Eisai v. Dr. Reddy's Laboratory and Teva Pharmaceuticals has begun to address this issue, and I'm not sure that I agree with the outcome. The case involved a pharmaceutical.

But first some background. With patents on pharmaceuticals and in general, chemicals, the "heart" of the invented molecule is clearly and usually narrowly defined, but is the patents will always claim one or more moieties, "sidearms", for which the exact chemical composition is not critical. The moities only need to have certain characteristics such as water solubility, inertness,... After reading just a few patents, any good chemist would get the idea and be able to see what is going on with the moieties. In fact, these moieties are such a popular idea that they have their own name: "Markush claims" named after the first case that included them nearly 100 years ago. It is commonly understood that the inventor does not actually prepare all of the examples, but just uses his knowledge and experience to claim that they would work.

In this case, molecule with a trifluorethoxy moiety was known in the published literature to work. Eisai filed a patent with Markush claims that dropped the terminal trifluorocarbon and replaced with with (amongst others) a monofluorcarbon. The stated opinion of the judges was "To the extent an art is unpredictable, as the chemical arts often are, KSR’s focus on these "identified, predictable solutions" may present a difficult hurdle because potential solutions are less likely to be genuinely predictable.”

So here we have it both ways: broad Markush claims are predictable, but narrow examples nearly similar to them are not predictible. I'd even be willing to bet that there are multiple patents were the Markush claims would list both the mono- and trifluorocarbons.

Markush claims have been getting broader over the years, now they will really spread their wings and soar.

Monday, July 21, 2008

Learning by Writing and not by Reading

In the Pipeline mentions backtracking in experimentation - going back and repeating what was done and checking all the details. While I have backtracked in cases such as this, I more often do so to fill in gaps that I didn't see in the original eperimental layout. In most cases, these gaps don't become apparent until the final report (or a progress report) is being written.

What is it about writing that causes such clarity? Certainly being able to express yourself clearly can only happen if you understand the concepts and results at hand, think about this: This whole concept is backwards, isn't it? How much writing is done in order to teach (textbooks, research articles), or if not teach, convince/persuade/sway (editorials and blogs)? In these cases, the "knowledge" is in the author and is passed on to the reader (yeah, this is the ideal case). But when learning occurs during the writing process, the conveyed knowledge loops around to the author again before eventually ending up with the final readers.

I recall an old bicycling racing teammate back at UIUC that was getting his master's degree in education that was writing his thesis on this area, so I've been kicking this idea around for a couple of decades. I've always wondered what would happen if I were to pre-write the final report before starting the experiment. It would require using fictictional number with reasonable values, but it might be interesting to try sometime.

Monday, July 14, 2008

Playing the Building

I always like David Byrne (of Talking Heads fame). He has enough of a unique viewpoint but not so much that he has lost it. He latest creation is a new instrument in Lower Manhattan - the Battery Maritime Building - an empty 9000 square foot space with exposed beams, pipes, rafters... By adding various actuators (vibrating motors, air blowers and percussion strikers) which are wired into the back of an old pump organ, you can now "play the building". Some of the parts were actually "tuned" so that a chromatic scale of sorts exists. While the building doesn't have the subtle nuances of Rachmaninoff's Second Concerto played by Jean-Yves Thibaudet, it still is a neat idea that such potential exists in an otherwise vacant building.

Apparently I am well behind the times as this site has been open since May and will be closing next month. So what else is new? I found out about this from Design News (July 14, 2008, Supplemental), a trade mag that I really enjoy. It's somewhat geeky (the Gadget Freak files is way too much) but I always make time for this mag much more so than any of the dozens of others that are on my desk.

Accelerated Aging - Getting Bad Data Even Faster - 1st in a Series

Accelerated aging is a laboratory technique for simulating long periods of outdoor exposure in a much shorter time period. This is typically done by exposing samples to various UV lights with or without occasional water sprays, and even some dark periods where the light is shut off. Since the UV lights can run 24/7 while the sun shines for considerably less time (most of which is not a peak intenisty) just running a sample under a bulb as luminous as the sun could give faster results, while having an even more luminous bulb could give even faster results.

I say "could" for good reason. This testing is far more complicated than it appears (my employer does lots work for people that don't do their accelerate aging properly). All the pitfalls are too numerous to mention, but one for starters:

1) Acceleration of the wrong failure mechanism When a part fails in the outdoors, there is a specific chemical or physical mechanism that leds to this result. It is critical that this specific mechanism is accelerated in the testing more than any other mechanism. If this isn't done, your results will be meaningless as you've accelerated a mechanism that is not of interest.

Thursday, July 10, 2008

Mixed feelings on PVC

My post the other day could give you the impression that I am in love with PVC. I am certainly not. Considering all the additives (plasticizers, UV and thermal stabilizers, internal/external lubricants, ...) that are needed (I did mention colorants as they are needed in all plastics) and the high levels of their addition, I've always felt that if PVC had been invented only last week, it would have been tossed aside as an academic curiosity.

It certainly is cheap. ~ 35 wt% of the polymer is tied up in chlorine atoms that are not a product of the petroleum industry so it is better able to weather price increases in crude oil. (Chlorinated PVC is even better situated with nearly twice the chlorine.) But I've always just found it a pain to work with, (the rheology of it is a nightmare compared to most thermoplastics or even thermosets) so that I have mixed feelings about the move away from it. I tepidly appreciate the move, but it is mostly being done for the wrong reasons such as the paranoia discussed previously. I find this disturbing as it rewards bad science, further encouraging more of it.

The Big get BIGGER

Dow is buying Rohm and Haas for 15.3 billion in cash at a 74% premium on the stock. It's a nice deal for R & H, but I'm not sure that Dow is getting much from the merger. Sure, the margins will be better than in many of the commodity plastics that Dow is already trying to move away from, but I don't see much of the valuable "synergy" that is desired in mergers. It almost comes down to Dow thinking that they can manage the business better than the the current management can. I've never yet met a manager who thinks that someone does a better job than they do (which is strange in comparison to scientists and engineers who for the most part will accept and state that someone else is a better scientist/engineer than they are), so time will tell. Dow's stock took a bit of a hit after the news was announced, so Wall Street seems to have doubts as well.

Wednesday, July 09, 2008

Don't drink the water

The last few weeks were doubly bad on the plastics-are-going-to-kill-us-all front. First, there was the your-shower-curtain-is-gassing-you-to-death-as-if-you-were-at-Auschwitz report that found lots (too much) media attention, but this is an easy target as the vinylphobes have been out and about for a couple of decades. It doesn't take too much effort to destroy the poor quality of the science in that report, but the Vinyl Institute has some points for starters.

But that's not all. It was also highlighted by the American Chemical Society that PVC water supply lines can lead to higher levels of lead in the water. It's not an obvious route to get from point A to point B, but it goes like this: Brass fitting often contain lead which can leach out at acid conditions which can occur more easily in PVC pipes than in copper pipes since the copper will inhibit the bacterial growth that lowers the pH.

So I guess the conclusions from all of this are:
1) Don't take a shower
2) Don't drink the water

Or maybe go with option 3) Relax and don't worry about it all so much.