Blam!

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There are quite a number of YouTube videos featuring explosions.  One that caught my eye recently features the reactions (explosions) of the heavier alkali metals, Rb and Cs.  The “experiments” could be legitimate, but with television you never know.  Then there is the lab demo of the reaction betwen bromine and potassium.  My personal favorite is the combustion of Magnesium in CO2 (Dry Ice).

Some years back I decided that I would treat my class to a demo on the reduction of CO2 with magnesium.  I had already done the Mg/CO2 demo before, but I learned in Bassam Shakhashiri’s book on demonstrations that the addition of a smidgen of potassium chlorate to the magnesium would assure that the Mg would ignite properly.  Make no mistake, Shakhashiri is much beloved in the chem educator field and rightfully so. His demonstrations are legendary.

I was a little uncertain of the wisdom of using potassium chlorate, so I decided it would be prudent to try out Shakhashiri’s modification in advance. One evening in my research lab I chiseled out a small indentation in a block of dry ice and added a Mg ribbon “fuse”, Mg turnings, and the recommended mass of potassium chlorate.  I ignited the ribbon and held the second dry ice block in front of me, ready to place it on the burning Mg.  As the burn reached the chlorate there was a blinding flash and a loud BLAM! When I opened my eyes I saw that the papers on the benchtop were ablaze and that the block of dry ice I was holding prevented burning Mg frags from lodging in my clothing. The air was cloudy with MgO dust, my ears were ringing, and expletives were flying out of my mouth.

Better that it happened in private than in front of 65 students. The students’ burns would heal.  But, more importantly, the damage to my reputation would have been horrific.

A few years later at an ACS meeting, in the mens room at the convention center in San Diego, I was standing at the urinal when who should take the urinal right next to me?  Bassam Shakhashiri.  I pondered the opportunity this might present.  Suddenly the moment passed and we both finished our business and went on with our day.  One of us nearly left with a wet shoe.

Melamine in Pet Food

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The issue of melamine in pet food has come up again as more lots of pet food are found to be contaminated with it.  At least a few news outlets have published a proposed reason for this contamination by a monomer from another industrial sector.  Melamine is very nitrogen rich- 6 equivalents per mole- so if you spike grain products with it you can cause the nitrogen analysis to read higher than it normally would.  Protein content is one of the factors in the pricing of animal feed, so an additive that would contribute to an uptick in nitrogen content would raise the price or even make a non-saleable lot of feed qualify for sale. 

The nitrogen test that most people think of is the Kjeldahl test.  It is a digestion-distillation-titration method that affords total nitrogen.  This test is still in wide use and is inexpensive to conduct.  A friend who has an Ag Lab still does the test on a bank of burners in his lab for total nitrogen in feed samples.

The practice of adulteration of foodstuffs not limited to China.  As an undergraduate I worked in a dairy processing plant lab and we had to screen for several kinds of mischief.  Dilution of milk with water is an old trick, given that pricing is on a per pound basis, so we had to test each raw milk tanker for total solids content.  We also tested for pH and temperature.

Neutralization of partially fermented raw milk with NaOH was also practiced at one time, so we taste tested each tanker as well since neutralization could not mask off-flavor.  Finally, we had to carefully screen raw milk for residual antibiotics.  Mastitis is an inflamation of the udder and has many causes. One aggravating factor is the common practice of milking ol’ Bessie three times a day.  A sick cow has to be taken off-line to recover. This reduces the productivity of the cow.

Farmers were often tempted to give sick cows a big jolt of antibiotic and get her milking again before the time needed to fully recover and clear the system of antibiotic. This could lead to antibiotic contamination in the tanker.  We performed two tests for penicillin at our plant. The microbiological test we performed was the Bacillus stearothermophilus disk assay. The other was a radiological assay called the Charm test utilizing C-14.  This test could be performed in 20 minutes, whereas the B. stearothermophilus test took 6 hours or so.  The newer Charm tests now take only a few minutes.

Residual antibiotics found in dairy products on the Grocers shelf could put a dairy out of business for repeated infractions. The state health authorities took (take) a dim view of penicillin in milk.

Nanosquat

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Th’ Gaussling is getting an eye-opening introduction to the maddening world high purity products and trace element analysis.  Multiple analytical methods seems to translate to multiple layers of confusion.  I’m a 3-Nines pilgrim in a 4-Nines land of opportunity.  Ya picks yer analytical method and ya stays with it.  Cripes.

It’s an alphabet soup of methods- GDMS, ICPMS, and XRF.  Gonna hafta crack the books again. Watch out. That shadow darkening the library stacks could be cast by a trustee of the f-block.

KSR Int’l v Teleflex, Inc. SCOTUS No. 04-1350

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The authors at Anticipate This! provide a good resource for those of us interested in IP and patents.  They have posted a summary of the recent KSR decision by the US Supreme Court.  If you’ve never read oral argument transcripts from the Supreme court, I would urge the reader to do so.  It’s fascinating.  No matter what you may think of the Supreme Court Justices politically, as a rule they are exceptionally sharp characters. 

We scientists spend very little time with lawyers and judges, other than for the usual public drunkenness or bitter divorce proceedings, so we may not have a calibration point for gauging their scholarly expertise.  Certainly reading transcripts or an actual decision will give the reader insights into who turns the big boat and what the rationale was.

I’m not a legal scholar- I’m more like a NASCAR fan.  I like to watch the legal wreckage go flying through the air and the pit crews scrambling for cover.  In this case, it looks like the USPTO may have to scramble to recalibrate the measure of obviousness.  Hey, pass me a beer …

BLEVE- Boiling Liquid Expanding Vapor Explosion

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There is kind of fire behaviour called a BLEVE– Boiling Liquid Expanding Vapor Explosion.  A BLEVE is what happens, for instance, when a closed container of flammable liquid is exposed to strong heating.  It can be caused by an external source, like a pool of burning liquid around the container, or it can result from a runaway reaction within a drum, cylinder, or tank.  The internal pressure builds up more rapidly than it can be vented and the containment fails, often explosively. It is interesting to note from the above link that boiling action of the liquid phase in the container absorbs energy and has a cooling effect, but there may come a point where the vapor pressure rise above the liquid exceeds the capacity of the relief discharge capacity and the vessel fails, discharging liquid and vapor across the burn zone.  At minimum, discharge and ignition will lead to a large flare, or if conditions are right, an actual detonation of the fuel/air mix could happen over a relatively large space.

These things often begin with some kind of tank or tanker accident (link updated 6/10/16) resulting in a discharge and ignition of flammable liquid.  As responders arrive they find a burning pool under or next to the tank(er).  Naturally, firemen and bystanders try to help those who may be hurt. As the minutes tick away and the fire becomes more aggressive and the tank gets hotter, the firefighters get their equipment in place and attempt to cool the tanker and suppress the fire.  Suddenly the tank fails and there is a prompt bulk discharge of liquid and vapor yielding a large fireball which may include an explosive shock, flying metal debris and a dangerous heat pulse.  It is at this point that the surviving bystanders and responders see the error of their ways.

Containers of flammable liquids rarely explode in a symmetric fashion so the container or its fragments are likely to be sent flying at high velocity, possibly spewing flammable material as it moves.  Even a relatively small volume of flammable liquid dispersed explosively can fill a large surrounding space with a fireball.

All chemical plants have their protocols for emergency response.  It is important for those in charge to recognize an incipient BLEVE and respond accordingly.  But even academic chemists should familiarize themselves with the phenomenon.  A fire in the lab engulfing closed containers of flammable solvents is extremely dangerous and very quickly firefighting may become your last earthly act, especially without personal protective equipment.  It is easy to under estimate the violence of these things.

Every lab person needs to look inward and decide what their personal limit is for dropping the fire extinguisher and running for the exit.  In my sophomore organic labs, the seed I planted in the students mind was this: The main purpose of a fire extinguisher was to fight your way to an exit.

Sacred Cows Make the Best Hamburgers

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I suppose I have lost more frequently than I have won in my lifelong avocation of taking on sacred cows in the battle of wits.  But, truly, sacred cows make the very best hamburgers.  Pass the A1 …

Some new blogs have been given a place of honor in the blogroll.  Good writing and laser sharp insight are the keys to this ascendency. If the dear reader is conservative and prone to weeping or bed wetting, it is probably best to click along at this point.  

There is a hilarious post over at Lawyers, Guns, and Money called Birthday Girl.  Side note: A lawyer friend is fond of saying “Lawyers, guns, and money- pick any two”.  

And then, what can I say about Jesus’ General?  Read General JC’s letter to the Secret Service re Cheryl Crow.  If you are keen on some serious in-your-face-atheism, check out Hellbound Allee. Then there is one of the best Christian evangelical lampoons ever, Landover Baptist. 

The Huffington Post is a recent find and is a treasure trove of political blogging at its finest- well, if you are a liberal.  Read the open letter to Rudy Giuliani by my fellow Coloradoan, Gary Hart. 

Then there is the Proceedings of the Athanasius Kircher Society.  The post on the Do-Nothing Machine is particularly amusing.  The reader may recall Th’ Gaussing’s previous post on the Katzenklavier. 

Finally, The Agonist has some interesting insights into politics and is well written. I also like Goosing the Antithesis for its skeptical stand against belief in the supernatural.

“Riding Rockets”- A Review

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I just finished reading Mike Mullane’s autobiographic “Riding Rockets“.  Mullane is a retired mission specialist astronaut with 3 missions under his belt.  It turns out that Mullane and I share one discouraging life experience.  I also wanted to be an astronaut and was also disappointed to learn in college (Air Force ROTC) that my nearsightedness would prevent me from getting a pilot slot in the Air Force or Navy.  Undaunted, Mullane went on to the next best option of GIB (Guy In Back) and became a USAF weapon systems officer.  His transition to astronaut from GIB was made possible by the NASA’s decision to eliminate the requirement of pilot experience as a prerequisite for mission specialist .  No doubt his degree from West Point, 150 combat missions in Viet Nam, test pilot school at Edwards, and a masters in aeronautical engineering helped him a bit.  I realized that I was a nearsighted, pathological smartass and left ROTC and went into chemistry.  Mullane persisted and got into space. I succumbed to the enchantment of organic chemistry and explored conformational space.

Mullane writes rather well and provides a reasonably balanced narrative over the time spanning his career. I would say that the main reason to read the book would be to get some insight into life in the astronaut corps.   If you put two people in a room, you have politics.  And it is no different with astronauts. Mullane details what can only be described as a byzantine system of decision-making for mission assignments and the characters who made these decisions.

Mullane describes in considerable detail the experience of a scrubbed launch. He bid farewell to his family and strapped a fully fueled shuttle to his backside 9 times for 3 launches.  Mullane tells of his own private fears and the fear that was (is) felt among many other astronauts- a feeling quite apart from the confident and laconic persona they might show in public. Indeed, he has been outspoken in regard to the safety of the shuttle fleet and in a manner uncharacteristic of astronauts, generally.

Far from being a monolithic group of superheros, the astronaut corp consists of a surprisingly diverse group of individuals.  As a group, astronauts are super achievers and not lacking the usual spectrum of attributes you might expect.  There is no shortage of ego or swaggering bravado.   Historically, astronauts come from an aeronautical background and as such, are accustomed to the flight environment and the norms that go along with it. During Mullanes tenure at NASA, the program saw civilian and other non-traditional astronauts take increasingly important roles in the mission.  In particular, this period of time following the first trial flights saw female astronauts accumulating a considerable number flight hours on orbit.

He describes in detail how the astronauts felt after the loss of Challenger and Columbia.  Mullane is of the opinion that the shuttle should have a better crew escape system.  Evidently he logged an ejection from an F-111, so he has first hand experience with bailout systems. There are literally thousands of parts and systems whose failure could tragically end a mission and the lives of its crew.  But like everyone who wants to fly in space, you swallow your fears and strap in anyway.

In the context of books in this genre, I’d give him a A- for his courage to be critical of NASA.  He now works as a motivational speaker.

Mixing and Unmixing

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Today was take-your-kid-to-work-day.  In honor of this we put on a chemistry show in one of the labs.  Burned some Mg ribbon, shrunk some balloons in LN2, blew up some balloons with dry ice, reduced iodine with ascorbic acid, and we unmixed some NaCl and carbon black. 

One of the barriers to teaching chemistry is a level of physical abstraction that is hard to get around.  It is hard to get around trivial explanations when the audience is not ready to discuss electrons.  Many of the really insightful concepts in chemistry are inherently abstract and age inappropriate for the younger crowd, so to compensate, chemistry demonstrations are often heavy in the whizbang components.  That’s fine.  It should be fun and visually appealing, especially for K-6. 

I like to do mixing and unmixing because it demonstrates something about materials handling.  It also represents an activity that occupies much of our time.  Separation science is not commonly called “unmixing”, but for chemistry demonstrations it causes kids to ponder the problem for a bit.  They all have experience in mixing things- we talk about that.  Then I ask the question “What if I asked you to unmix that KoolAid”?  A few of the more worldly ones might suggest boiling off the water.  But most kids seem to be stumped- they will admit that they would have never considered the possibility of unmixing. 

So we dissolve some NaCl in water and make a solution.  The use of a magnetic stirrer and stirbar makes way for a minor diversion with magnets and iron filings. Then we blend in a bit of carbon black. Using a Buchner Filter, filter paper, and Celite, we do the vacuum filtration, showing the remains of the carbon in the Celite.  The filtrate is then treated with some “Anti-Solvent” like acetone and the salt comes crashing out. 

Yeah, I know. It is pretty tame.  But it can be done cheaply in 45 minutes and the kids can see their parents actually doing something. 

Jane Goodall

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Went to a public lecture by Jane Goodall last night. The arena was packed.  She and members of her institute have found a type of formula for combining conservation and economic growth.  At some point she realized that you can’t sell conservation in a vacuum.  People who live near fragile preserves like Gombe have to make a living.  They need food and firewood. 

Human population pressures also threaten the shrinking wildlife preserves all over the world and in Africa in particular. One way to encourage lower population growth is to look after public health and, in particular, the welfare of women. They’ve noticed that families naturally tend to have fewer babies when infant mortality rates lower. Lower mortality rates can be achieved through the application of very fundamental improvements in hygiene and health care.

One of the critical approaches they are taking in Africa is to improve the life of women through micro loans.  This has proven effective in many other parts of the world and Goodall reports it is having a beneficial effect in Africa as well.

As I sat and listened to the lecture, I was overcome with the futility of our ever increasing consumerism.  Take our collective response to the increasing scarcity of petroleum.   The big ideas seem to involve finding new ways to sustain high consumption- e.g., the replacement of petroleum with ethanol or hydrogen.  The idea that we might have to throttle back our per capita consumption of stuff extracted from the ground is ignored.

Well, of course the national stage isn’t filled with people promoting reduced consumption.  There is no money in reducing demand. Who wants to hear that? 

Minimally, the USA must go the way of Europe in terms of lower average consumption.  Higher population density combined with higher priced energy will lead to more modest consumption of goods due to lifestyles adjusting to scarcity. 

Intermission

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I’m up to my gills in really fascinating stuff at the day job, but none of it can be blogged.  Pity.  So I have to blog about silly links and make fun of POTUS.  I hope the reader will pardon this intermission.  Here is a platitude shamelessly lifted from Making Light–

“The whole point of society is to be less unforgiving than nature.”  

Amen, brother.