Monday, September 27, 2004 Deadly Nanocarpet

It not only changes color when it encounters different chemical agents, it can kill bacteria. How neat.

Friday, September 24, 2004

Holey Fibers, Batman!

Actual title: Holey Fibers Shed New Light by Chelsea Wald Physical Review Focus 9/20/04
This is actually pretty neat - they've found a way to convert commonly available laser light into some of the wavelengths they hadn't been able to make a laser in. There are some valuable biomed applications, apparently. The primary article is F. Benabid et al., "Ultrahigh Efficiency Laser Wavelength Conversion in a Gas-Filled Hollow Core Photonic Crystal Fiber by Pure Stimulated Rotational Raman Scattering in Molecular Hydrogen" Phys. Rev. Lett. 93 (2004). DOI: 10.1103/PhysRevLett.93.123903

Searching for Math Equations and Symbols on the Web: Part 2

Ok, so I talked about searching for math represented on the web using entity and code values (those starting with an & and ending with an ;). What about pages like this one, just mentioned in the new edition of The NSDL Scout Report for Math, Engineering, and Technology v3 n20 (September 24, 2004)? If you "view source", you'll see that they use .gif files for the math. This particular page uses the word curl several times, but there's no alt for the image, so there's less information for an image search engine to use. Don't even try to search for curl, but if you try grad OR gradient in Google images, on the second page of the results, you'll get someone's handwritten notes. The collection of images in Yahoo seems much smaller - you do get handwritten notes if you enter curl math. If you call the symbol I've been calling grad by it's more generic name "del", you'll actually get a couple of equations, interestingly enough. Google yields a few results with del math. See one interesting one: . AltaVista is apparently still using it's own technology and collection, but the results are not much better.

So, what about the new(er) image searches that analyze the picture itself instead of just the context and alt text? Those that do feature extraction? Can they pick out an integral? or a gradient? The one at Columbia I knew about a while ago is apparently down (websEEk). The one at Penn State by Wang and Li runs only on a practice set of images - and they're from a cd of clip art. (Actually I'm having a hard time finding any of these so I just posted a request to a list for help.) (found via SearchEngineWatch, I don't know if it's content based)
This one does better. If you cut and paste the ∂ or the ∇, it actually comes up with mathematical equations. Now, what if we try ∂x/∂t ? Nothing, but ∂x does yield ∂x . It's a start but I 'm not going to try to narrow the results!

I'll add to this (hopefully) when I find some other engines.

Searching for Math Equations and Symbols on the Web: Part 1

NB: I derive an almost perverse pleasure in torturing search engines. Please also note that I'd like to form this into a paper for publication so I'm calling dibs on my ideas (link, disagree, comment, expand upon ... but please don't copy and republish)

It came to me that I'm sure there are a ton of web pages out there with papers talking about div, curl, grad, summation, integration.... all these things best described by their equations and symbols. Mathematicians frequently solve and prove solutions to equations divorced from the applications of the equations to describe nature. Physicists develop new equations to describe nature and then try to solve them, engineers look up solutions to equations to solve real, immediate, application problems. So, how can physicists, engineers, and librarians search for math stuff on the internet if the writeups and the equations themselves do not use the language of the physical phenomena the equations describe? Or if the equations are not yet named and famous? Or are not recognizable as belonging to the physical phenomena?

You can search in Safari by code snippet and in chemistry databases (like the ChemIDplus from NLM) by substructure. (You can also try the ACM Portal with code snippets, but there's no real way to search the open internet for chemical structures.) That's pretty cool, but what about searching for a particular mathematical formula? In Inspec and MathSci Net, the subject headings are probably the best access points and there are rules for representing symbols (like /sub/ depending sometimes on the vendor) – but this doesn't help if the mathematical formula is not linked to the particular phenomenon you're studying. I discussed in an earlier post how there are various ways to represent math on the web. So, what happens when you search for ∑ or & sum; or & #8721; ? Maybe sum isn't the best choice because normally you'd have an n=a somewhere attached so I'll also search for the partial derivative symbol ∂ and the gradient ∇.
Graphic symbol pasted in – does nothing, not even an error
Name code or entity (starting an & and end with a ; ) – returns mostly tables and posts on how to use MathML or the codes or various things from computer programming. For the partial derivative symbol (∂), Google returns nothing on the code (& #8706;) and returns non-math stuff for the entity with one exception - an improperly created abstract that actually shows the code, not the symbol.

Graphic symbol pasted in – zero results.
Name code or entity – Yahoo ignores the & and the ; and searches for Sum, or part, for the entity and the numbers for the code. You end up with phone numbers, part numbers, etc.

Graphic symbol pasted in – lots of results, it's seeing them all as empty boxes, so it's finding non-romanized language pages.
Name code or entity – Teoma apparently ignores the & and the ; and searches for sum, or part, for the entity and the numbers for the code. Quotes don't help.

Thursday, September 23, 2004

NY Times: Drawing Semiconductor Circuits, One Tiny Line at a Time

by Anne Eisenberg 9/23/04
It's like a nano glue gun. A new way from NRL and Georgia Tech to do nanolithography that uses dip pen technology on the tip of an atomic force microscope. From this article, what's new is that they can turn the writing on and off by heating and cooling the tip and having the "ink" solid at cooler temperatures... you know, like a glue gun. Their full article is Sheehan et al "Nanoscale deposition of solid inks via thermal dip pen nanolithography" Applied Physics Letters v85 n9 (30 Aug 2004): 1589-91.

I'm not quite sure how their version differs from the one described by Bullen et al in "Design, fabrication, and characterization of thermally actuated probe arrays for dip pen nanolithography" Journal of Microelectromechanical Systems v14 n4 (Aug 2004): 264-602

A side note: Inspec has a heading for nanolithography. Cool.

Wednesday, September 22, 2004

ChemIDplus, Now Updated With More Information

Pointed out on ResourceShelf.
ChemIDplus is the National Library of Medicine's chemical dictionary. It covers 370,000 chemicals (# from help file, higher than # in press release). It allows property searching, substructure searching, CAS RN searching -- all paid for by US tax dollars, and free to the world. They've recently updated the search and added more chemical property fields.

Monday, September 20, 2004

The Industrial Physicist: Scramjets integrate air and space

by Dean Andreadis. (Aug/Sep 04): 24-7.
This is a nice, understandable overview article on scramjets. It discusses the differences between scramjets and ramjets, turbofans, turbojets. Shows the parts of the scramjet. Provides a laundry list of terms.

Friday, September 17, 2004

Call for Assistance/Input/Comments

Two colleagues and I are presenting at the upcoming Greater Washington Nanotechnology Alliance Fall 2004 Special Topics Symposium (agenda not posted as of 9/17/04). Our topic is:
“Finding the Vocabulary and Literature of Nanotechnology.” Basically, the idea is that this is a new and fast moving field that crosses biology, chemistry, physics, etc. The standard databases in these areas have coped in different ways and have added or failed to add indexing to support searching. Also, there are specific methods that are useful to search the internet to find information in these topics. We'll discuss the current state of literature and web searching on scientific (not business, patent, news) nanotech topics.

If you're interested in a related article on this subject, ask your library for Rick Weiss, "Language of Science Lags Behind Nanotech; Burgeoning Field in Need of Universal Way to Describe Creations," Washington Post (May 17, 2004): A07.

If you would like to offer suggestions or preferred strategies on any of these topics, please comment here, link to this post, or e-mail me at cpikas (at) gmail (dot) com. I'll cite you if you like and post some results here.

I'll probably be asking questions of the various listservs, so please pardon any duplication.

Thursday, September 16, 2004

e4engineering: Not a Pretty Picture

9/16/04 (via feed).
This is just the most recent of a ton of recent reports on this security hole. I'm posting here because for the last couple of months or so I've been intrigued by steganography (see overview here: It's conceivable that this hole exists for other browsers/operating systems. Niels Provos is (was?) marketing a product to check jpegs for steganographic content. It seems that the spamfilters kind of need to incorporate this. Maybe they do already?

Wednesday, September 15, 2004

PhysicsWeb: Petroleum under pressure

Scientists have made methane through inorganic reactions... and have monitored the reaction in situ through diamond surfaces.
"Freeman Dyson of the Institute for Advanced Study in Princeton believes the results are important because they could help answer the question of whether natural gas and petroleum could be created inorganically. 'If the answer turns out to be inorganic, this has huge implications for the ecology and economy of our planet,' says Dyson.
However, Scott is more cautious about his team's results. 'Although I believe the Earth's mantle could contain a significant quantity of even heavier hydrocarbons, I cannot constrain how much of this reaches the Earth's surface, or the extent to which it may augment resources that we exploit commercially,' he told PhysicsWeb. 'I do not want to suggest in any way that these hydrocarbons are likely to represent an untapped energy reserve.'"

New Journal of Physics: Focus on Turbulence

Found via the IOP feed. Should be available free of charge.
One of the foci of the current issue of the New Journal of Physics is Turbulence. It includes about 15 articles now and more will be added. Per the editors, the purpose is to
address ... basic questions in turbulence theory, experiment, computation and modelling, highlighting where progress has been achieved, and where it can be reasonably expected within the next few years.

Monday, September 13, 2004

BBC NEWS | Technology | Students make washing machine talk

9/12/04 by Geoff Adams-Spink (via their RSS feed)
This should have been done long ago. But I trust my washer to keep my secrets.
Update: Ok, I can't help it "we have ways of making you talk"

Free Full-Text Journals in Chemistry

The compiler, Alexander Ragoisha, just reminded us of this resource on [CHMINF-L].
All links and comments had been verified in August 2004. It was a surprise to me that less than ten journals died or closed free access to full texts since August 2003. Moreover, every forth journal of the list has expanded in free cyberspace.

As in the previous year, I plan to add new information to the site twice a month.

The New York Times: Let a Thousand Ideas Flower: China Is a New Hotbed of Research

by Chris Buckley 9/13/04 (free registration req)
Initially, this seems pretty simple: the big funders of research outside of the government are outsourcing their R&D overseas to save money. It is probably more complex and the gains are perhaps not all that they had hoped. First, we may be encouraging this with our more strict immigration policies since 2001 (look at grad student attendance). Second, one person in this article says that the IP concerns and management concerns make it like herding cats.

Still, now that it's not just manufacturing jobs leaving but creative jobs, it's definitely worth being on the radar.

Thursday, September 09, 2004 Researchers Spin Nanotubes Into Fibres

From Design Engineering (found on e4eng feed) 9/9/04
Cool! We're that much closer to our space elevator. Ok, quick review. Carbon nanotubes are really strong but clumpy. They're also brittle. They need to be made into fibers or ribbons to be useful in a somewhat pure form. Looks like researchers from Penn and Rice (a nanotube HQ) have figured out a way to do it. It's similar to the way Kevlar fibers are made. (The original article actually came out in December: V.A. Davis, et al. "Phase Behavior and Rheology of SWNTs in Superacids." Macromolecules v37 n1 (2004): 154-160. DOI: 10.1021/ma0352328.)

Wednesday, September 08, 2004

IEE Electronics Systems and Software: Filling in the Gaps

by Bill Collis and Anil Kokaram v2 n4 (Aug/Sep 2004): 22-8. (in print, the download is PDF, 884KB).
This is a pretty neat article describing post-production image processing to do "motion interpolation" and "image synthesis." Basically, automated removal of the camera rig from the frames and in-painting to fill in a crowd.
The algorithms described in this paper have been implemented as plug-ins by the authors and are now in widespread use within the post production community. Film credits include The Matrix films, the Harry Potters, Lord of the Rings, and many others, although part of the success of these techniques is that the average viewer is unaware of their use in a film.

Washington Post: Vehicle-Profiling Technology Speeds Up Fast Food

by Charles Sheehan AP 9/8/04 (pointed out via e-mail newsletter, free registration required)
No, not that kind of profiling! This is non-invasive, image processing of feeds from roof cameras pointing at the parking lot. Looks at the size of vehicles and number of vehicles predicts need for more Big Macs.

National Hurricane Center RSS Feeds

This seems like a particularly good example of e-gov and of a government agency using new methods to communicate with the citizenry. Here are the feeds:
Atlantic (English):
Atlantic (Spanish):
Eastern Pacific (English):