Post Tagged with: "NMR"

New manufacturer of NMR instruments to enter the market

With the exit of Agilent from the NMR instrument market there’s a gap that is in desperate need of filling. Now it looks like a rather unusual group is considering plugging the hole. The company, usual associated with construction but also happens to be the largest manufacture of tyres in the world, is conducting a poll to see whether NMR is a viable option for them.

If you think the chemistry community needs a new NMR instrument manufacturer then please pop over to their website and let your thoughts be known.

 

1752124-o_19bn8ufoonppi5kkq1m2t1lkp7-full

 

Update:

The lego NMR instrument now comes with mini figures!

 

 

By January 19, 2015 0 comments fun, general chemistry

One for the Christmas list

In my last post I heaped praise on “The Wonderful Life of Elements“. Well, how fickle I am. Within three short days I have a new favourite. Now don’t let the title  “Chemical Shifts and Coupling Constants for Silicon-29” (Gupta et al.) nor the drab cover put you off. This book is undoubtably a work of genius.

I’ll let the Amazon reviews speak for themselves. After all I certainly can’t do a better job of demonstrating how undeniably useful this book is. Take Mr. E. Welsby’s glowing  testimonial for instance:

At the Boston inst of chemical tech we’ve been looking for ways to expand silicon usage for construction, thanks for the bonding information of this book we’ve successfully managed to merge silicon atoms with that of a small gibbon, who can now phase his physical body between carbon and silicon (sand) at will.

and the equally enthusiastic praise from  K.V. Trout:

I don’t know how they came up with the idea to do a book on Chemical Shifts and Coupling Constants for Silicon-29, but I would have never thought it would be worth this much money. These guys are visionaries, because at a time when the rest of us were watching sit-coms and wondering who was going to win American Idol, these guys were gathering together the numerical data and functional relationships of various technical and scientific kadoodleybobs.

I bow to their marketing genius as well as their forward acuity in the sci-market arena. Their discomprietary diagnosis of the current shift in ascracaciousness, is beyond imageration.

Author! Author!

Granted not everyone is quite so keen. But there’s always some naysayer isn’t there?

My ex-wife and I were both big fans of Silicon-29. However, after reading this book, her opinion changed…As a huge fan of superfluidity and quantum entanglement, I found that living with a woman who didn’t accept these theories as fact was intolerable. My ex-wife kept referring to this book as a source for all her arguments against these two well established theories. I mean, who can really trust anybody who doesn’t believe 100% in the Einstein-Podolsky-Rosen paradox (which apparently Gupta and my ex wife do not). Before reading this travesty of a book, my wife was on board with the uncertainty principle…. Well, thank you very much Gupta for this book, a diatribe of garbage, which inadvertently change my wife’s opinion on everything.

Okay so $7,371.84 (reduced from £7,679) might be a bit of a sticking point, but what self respecting PI or lab manager would deny her group this astonishing book. Surely we all have the dregs of a research grant or an end of year underspend that would cover the cost nicely?

 

By September 27, 2012 3 comments fun

Coin Flip Game to Teach NMR Coupling and J-Value Concepts

One of the most frustrating units for me to teach in my sophomore organic chemistry class is the coupling/j-value concept in the NMR chapter. Going through the tree diagrams, we can get to a place where we understand that 3 neighboring protons cause a quartet, but I’m not convinced they really understand why. It gets worse when we get to doublet of doublets. This really goes way over their head. So I delve deeper into the theory so it will become more clear, but the concept only becomes more muddy in their mind. So I go even deeper, really getting into the physics (a class many of them haven’t taken yet), and their eyes start to glaze over and I start to lose the class.

By the end of the unit, we all resign and the students end up ‘memorizing cases’ with little to no understanding of why. I hate ‘memorizing cases.’

So last week I had an epiphany on the drive to work. I was thinking about how to make the concept more clear. Given a proton with a chemical shift, the random up or down spin state of the neighboring proton influences the chemical shift of the observed proton and offsets the chemical shift by an equal value in the positive and negative direction. Total values… a binary up/down spin state… offset by equal amount. Coins!

Given a quarter with a ‘chemical shift’ value of $0.25, a flipped penny will either land heads up or tails (heads down). Say a heads up penny adds $0.01 to the total value, and a heads down penny subtracts $0.01 from the total value. Flipping the penny thousands of times and keeping a running tally of the occurrence of the total values will give a statistical 1:1 ratio of total value $0.24 or $0.26. Flipping two pennies thousands of times will give a statistical 1:2:1 ratio of total values $0.23, $0.25, or $0.27. The analogy is perfect! And if you flip a nickel instead of a penny, we can even draw an analogy to j-values!

I was really excited about my new teaching tool, and began thinking about how to implement it in the classroom. Do I just talk it through as a pure thought experiment? No, they’ll drone me out. I can bring in a penny for everyone and we can predict outcomes, flip, and discuss as a class. Then pair up and play again with two pennies and discuss. That would work, and be interactive. But the relationship to NMR may still be fuzzy. It’d be nice if they could run lots of simulations with lots of combinations of coins on their own time…

Now, I’ve been participating in Code Year by Codecademy since it started in January. It’s been awesome. The first module in Code Year was JavaScript, a language I didn’t know but had always wanted to learn. My dad taught me BASIC when I was a kid, and I taught myself html and CSS, but I never knew JavaScript. I’m still not an expert, but I can code my way around JavaScript fairly confidently now, thanks Codecademy and Code Year!

So, feeling cocky with my new JavaScript tools, I thought this would be an excellent playground for me to test my new coding ability. If you want the entire story about how I created the site, all the gory details are below the jump. Many of you will not care. But after working on it for a week straight, it’s finally ready to launch. Here’s the game. Feel free to play around and see what you think.

Play 5 times to earn a link to a page digging into the theory.

If you teach NMR, and if you want to use this in your class, feel free to! I haven’t tested this out with an actual class of students who have never seen coupling/j-value yet, so we’ll see how it lands when I launch it for real 🙂 Hopefully the days of not understanding coupling/j-value are over!

If you have any comments/suggestions/improvement, I’d love to hear them!

Read more ›

By June 7, 2012 14 comments chem 2.0, chemical education

Helium for balloons but none for my NMR

Our reserves of helium are finite and we’re running out. This may come as a mild disappointment to children everywhere but its really bad news for science.

My (and everyone else’s) NMR machines use liquid helium (at 3 Kelvin) as the coolant for their superconducting magnets. The same goes for MRI scanners and those cathedrals of science the particle accelerators like the LHC. And right now there’s a world wide shortage of helium which means that we may have to decommission some of our NMRs. Re-commissioning them will then cost 10s of thousands of dollars, plus it would require huge amounts of liquid helium to cool them down again.

We fill these instruments with liquid helium regularly, replacing the stuff that’s boiled off. The thing is that once that helium has evaporated off and into the atmosphere its gone. There’s no getting is back. So why don’t we bother collecting the boiled off helium? All we’d need to do is stick a balloon on top of the NMR machine, then a simple compressor could be used to turn it back into a liquid.

We don’t bother with this simple bit of recycling because there’s no immediate economic imperative. But hang on, didn’t I just say the reserves are limited, so surely helium is really expensive? Well it aught to be. According to Professor Robert Richardson, who won the Nobel physic prize in 1996 for his research on helium, a helium party balloon should cost $100. Instead they cost about 50 cents. The reason helium is sold well below its ‘real’ value is because of an odd law passed by the US congress in the 1996. Robin McKie explained some background in The Observer newspaper last month.

 In the 1920s the US decided helium would be a strategic resource. It realised that air power would be crucial in future wars, and assumed that these would be fought by airships that would use helium to float.

Then to cut costs in 1996 Congress passed a law mandating the U.S. helium reserve (the largest in the world by some way) be sold off by 2015, irrespective of market price. They set in stone the amount of helium that needed to be sold and so ever since they have been dumping it on the market.

This is a long term issue, but it doesn’t explain the immediate shortage. The problem here, as far as I can gather because our suppliers (BOC) aren’t telling us much, is that several of the worlds helium refineries are out of action. That, at least, was the case 10 months ago according to gasworld.  And they don’t expect things to improve until a new plant comes on line in 2013.

In the meantime it looks like there’s going to be a long queue for the remaining NMR machine.

25th April UPDATE :

Here’s the latest on the helium situation from BOC in the UK.