Teflon heat-exchanger tube bundles, such as this one, are flexible and slip easily into shells that are available in a number of materials, ranging from carbon steel to Delrin acetal resin. A typical bundle would have some 1300 tubes, encased in a shell 4 ft. long, and about 5 in. in diameter.
Teflon Makes Strides in Heat Exchangers
Multiple, small-diameter tube concept enables Du Pont to design around Teflon’s thermal conductivity limitations
“I can’t go home smelling like a meth lab,” Walt says, as he strips down and dons a lab apron. Credit: Doug Hyun/Sony Pictures Television
Chemistry is the study of change, lectures Walter White, a high school chemistry teacher in Albuquerque, N.M. Electrons change their energy levels, molecules change their bonds, and elements combine and form into compounds. That’s the cycle of chemical life. “It is growth, then decay, then transformation,” he says.
So says the brainchild of Vince Gilligan, creator, writer, and producer of a new television series, “Breaking Bad,” on the AMC cable network. In the show, 50-year-old Walter—Walt to his friends—discovers he has inoperable lung cancer and is given two years to live. He turns to making methamphetamine to finance his family’s future, partnering with a former student and setting up shop in a recreational vehicle.
…“Walt truly loves chemistry,” comments Gilligan. “It’s one of the few things that have kept him sane for his whole life. There’s so much slipping from his fingertips and falling apart at the seams, but chemistry is always there.”
In addition to scenes of meth synthesis, chemistry is front and center in other parts of the show. In the second episode, Walt has Jesse dispose of the body of a deceased meth dealer by dissolving it in hydrofluoric acid. Jesse, unfortunately, ignores Walt’s orders to use a polyethylene container and instead puts the body in a second-floor bathtub. The acid eats away the tub and floor, raining body parts and gore below. In the sixth episode, Walt substitutes crystals of fulminated mercury for meth, then uses them to create an explosion. The display encourages a drug distributor to agree to Walt’s terms.
A self-described science groupie and reader of Popular Science and Discover, Gilligan says getting the science details correct is important to him. The idea for using fulminated mercury stemmed from the 1955 movie Mister Roberts, in which one of the characters uses the substance to alleviate boredom by setting off explosions on a U.S. Navy ship. Gilligan and his fellow “Breaking Bad” writers determined that fulminated mercury makes crystals somewhat similar to crystal meth, so they’d pass as a substitute. “Hopefully this is correct,” Gilligan says, noting that a lot of the science information in the show was researched on the Internet because the show’s budget didn’t allow for a paid chemistry adviser. He welcomes constructive comments from a chemically inclined audience, he adds.
The show did seek out advice from the U.S. Drug Enforcement Administration (DEA). An Albuquerque agent advised how to set up a raid on a residential meth lab in the pilot episode, and senior chemist Victor Bravenec of DEA’s South Central Laboratory, in Dallas, helped set up the RV meth lab. “What they wanted was not how a regular person would make methamphetamine but if I were to make meth, how would I do it? How would a chemist do it?” Bravenec tells C&EN.
Bravenec’s contributions show in the glassware choice and apparatus setup as well as in how pseudoephedrine is ground and solvents are poured. He also worked with the special effects and art departments to help ensure that solutions and glassware stains looked real. Bravenec notes that Gilligan was very sensitive about not making the show a “how to” video for cooking meth, so key components are left out.
-Jyllian Kemsley
‘Breaking Bad’: Novel TV show shows chemist making crystal meth
A laser beam directed through a grid and into a microscope bleaches dye molecules in a membrane, superimposing a striped pattern. Its rate of spreading is a direct measure of molecular lateral diffusion, according to McConnell and Smith.
Membranes: Key Players in Immune Response
Destruction of foreign cells depends on recognition sites on their membranes; chemical ways are evolving to study properties of the membranes
The body’s immune system, charged with the task of recognizing and destroying invader cells, is a chemist’s nightmare. Its varied components, including proteins, glycoproteins, cascading pathways, numerous cell types, and obscure factors, make up a seemingly medieval compendium of incantations and special dialects.
Yet, a few courageous apostate chemists have joined earlier converts in a determined effort to translate immunology into a vernacular tongue, to make chemical sense out of biological cant. A prime target of those efforts—indeed, a prime target of the immune system when it resists an invader—is the membranes of cells.
One of the principal acts of the immune system is to poke holes in membranes of cells that invade the body. That concept, simple as it sounds, has not been simple in the making. Nor is it fully understood how the immune system assures itself that a particular membrane is a target worthy of attack, rather than an innocuous membrane best left alone.
Scrutinizing target cells and their membranes is, in many ways, impractical. The chemistry of such cells is intricate but not uniform. Thus, chemists have chosen to abide by the wisdom exercised by anyone starting serious target practice: Make the target simple.
Dr. Harden M. McConnell and his many collaborators at Stanford University have put that wisdom into practice by devising chemically simple targets for the immune system to attack. Their targets consist of membrane vesicles, which are spheres of a single phospholipid bilayer, and of liposomes, which are multilayered phospholipid spheres. The composition of such targets can be controlled. Thus, for example, the phospholipid mixture may be varied; spin-label probes may be added; those molecules or others may be used as the recognition sites (the antigens) for other components of the immune system; and the targets may be made and loaded at will with appropriately chosen markers.
-Jeffrey L. Fox
Ben Lichtenstein makes a postpolishing inspection of lighting fixture “arms” at Los Angeles plant of Scovill Manufacturing Co.’s Lightcraft division.
“We can now make a few milligrams of anything whose structure we can draw, that is stable, and that has fewer than a thousand atoms. Molecular recognition and design are the next great frontier of organic chemistry,” says W. Clark Still. The Columbia professor delivered that assessment to the Leermakers symposium on the current state of organic synthesis held at Wesleyan University. He described to the symposium synthesis of the barely stable thromboxane A2 and his work on molecules with chiral cavities that may someday resolve racemates and complex separate peptide sequences.
…In Still’s research, the thromboxane A2 (TXA2) is made by blood platelets from arachidonic acid and oxygen. This highly unstable bicyclic ketal triggers platelet clumping in formation of blood clots. The action of TXA2 is countered by prostacyclin, also called prostaglandin I2 (PGI2). PGI2 is made in cells of arterial inner walls, also from arachidonic acid and oxygen, and inhibits platelet clumping. TXA2 and PGI2 strike a delicate balance that normally promotes wound healing and whose disruption may cause cardiovascular disease.
Because TXA2 decomposes with a half-life of three to six minutes in blood plasma, Still turned to Stuart Bunting and Frank A. Fitzpatrick of Upjohn Co. for bioassays to verify the identity of his product. Bunting and Fitzpatrick generated synthetic TXA2 from Still’s stable precursor and found that it had the expected half-life, caused platelet clumping, did not cause clumping of other blood cells called neutrophils, and did not stimulate biosynthesis of leukotriene B4—all properties expected for TXA2 that would distinguish synthetic TXA2 from other compounds.
Still’s synthesis began with the methyl ester of TXB2, which is a TXA2 metabolite diol, and which he cyclized to the ketal. The Columbia chemist planned to insert a bromine atom into TXB2, which would ease cyclization, and which he would remove later in a free radical reaction with tributyltin hydride. In practice, the radical reacted internally with a double bond in one of the two side chains.
Still solved the problem by first closing a 13-membered lactone of the carboxyl group of one side chain and a hydroxyl group of the side chain that contained the double bond. His molecular mechanics calculations indicated that the conformation of the lactone would position the double bond away from the radical. Still has accomplished several difficult syntheses by strategies that control successive conformations of macrocyclic intermediates.
-Stephen C. Stinson
Organic Synthesis Looking to Molecular Recognition and Design
Scientists respond to mistreatment of fellow scientists and political intrusions into world science as controversy rises over proper role of scientific societies
…Despite the considerable number of Soviet scientists who have emigrated, it is by all accounts much harder for scientists than nonscientists to obtain exit visas. “At least every second scientist who applies for an emigration visa is refused,” at least initially, notes Mark Azbel, a former refusenik leader who reached Israel last year. “For example, I don’t know a single physicist with an advanced degree who applied and was not refused. The more education, the lower the chances.”
Beleaguered Soviet scientists include (from left) refuseniks Irina Brailovsky (threatened by officials along with her husband Victor, scientific seminar leader), Joseph Begun (jailed for “parasitism”), and Aleksandr Lerner (called a CIA agent along with Scharansky by Soviet press), and human rights leader Yuri Orlov (jailed for the past year without formal charge or trial).
In most cases, when a scientist applies for a visa, he is dismissed from his job, cut off from laboratory, library, and lecture hall, ostracized by colleagues and students, and prevented from publishing his work. His telephone is disconnected, his mail is impeded, his apartment may be bugged and put under surveillance, and he and his family are subjected to various kinds of harassment. He, in fact, becomes a “nonperson,” with even mention of his name eliminated from scientific journals and books. And “all this is in a situation of constant threats and pressure,” emphasizes Azbel, who waited five years for an exit visa. “And you never know when the threats will become reality.”
In short, the refusenik scientist enters a state of limbo for an unknown time. And if he cannot find approved work in the state-run economy, he becomes liable to trial and imprisonment on charges of “parasitism” (having no visible means of support).
Indeed, protests concerning one such case are currently being organized by the Committee of Concerned Scientists (CCS), that of Dr. Joseph Begun, an electronics engineer and mathematician, who has been sentenced to two years for “parasitism.” CCS is also actively pursuing, among others, the cases of cyberneticists Aleksandr Lerner, Grigory Goldstein, and Victor and Irina Brailovsky, physicists Vladimir Kislik and Naum Meiman, microbiologist Oleg Milshtein, and molecular biologist Vladimir Raiz. The American Association for the Advancement of Science also has taken up the cases of Begun, Lerner, Kislik, Meiman, and others. ACS has repeatedly protested treatment of noted physical chemist Veniamin G. Levich, and is studying the case of refusenik chemist Galina Shmelyova. And the Federation of American Scientists has organized campaigns for Soviet scientists, among them dissidents Kovalev and Tverdokhlebov.
Besides lower chances of being allowed to emigrate and a longer wait, “scientists are in the worst position” of refuseniks from another, point of view, Azbel stresses. “It is very easy to become dequalified.” Indeed, he says, “everything is done to destroy their scientific effectiveness.” And, recalls Stone from his Moscow visit, “They were all quietly dying as scientists and it was frightening. In a few years, they won’t be able to do scientific work.”
Polymer chemist Hershel Markovitz of U.S. (left) lectures to seminar in Moscow of scientists refused emigration visas, including (foreground, from left) Victor Brailovsky, Veniamin Levich, and Mark Azbel (Azbel is now in Israel).
To maintain as much scientific viability as they can, the refuseniks have therefore organized regular weekly seminars in Moscow and other cities, where they present for discussion their own (necessarily theoretical) research and hear lectures on world developments from visiting western scientists. About 200 foreign scientists have visited the largest and most active group, an interdisciplinary Seminar on Collective Phenomena held in Moscow in private apartments on Sundays since 1972. For example, Dr. Hershel Markovitz of Carnegie-Mellon University gave several lectures on polymer chemistry. Azbel led this seminar, and Victor Brailovsky is the current leader.
Azbel and other former refuseniks stress how vital the seminars are to the refuseniks for both science and morale. And they urge scientists who visit the U.S.S.R. to attend seminars: “It really helps.”
-Richard J. Seltzer
Selection for design, 20th Annual Exhibition of the Art Directors Club of Metropolitan Washington, 1965
Barbados Oceanographic and Meteorological Experiment seeks mechanism of sea-air interaction
As the British were invading Anguilla late this month, another Caribbean island, Barbados, braced itself for a different kind of invasion from the U.S. Called BOMEX for Barbados Oceanographic and Meteorological Experiment, this scientific expedition will get under way on May 1 and last for three months. Commerce’s Environmental Science Services Administration—the lead agency for the project—bills BOMEX as “the most intensive scientific investigation ever made over a large ocean area.”
Flipped vertical in BOMEX, the Floating Laboratory Instrument Platform (FLIP) will have 300 feet of its 355-foot length under water.
And well it might be. During May, June, and July some 1500 people will gather data using 24 planes, 10 ships, seven satellites, a dozen buoys, and FLIP (Floating Laboratory Instrument Platform). The scientists and technicians will cover 90,000 square miles of the Atlantic east of Barbados and investigate the air to altitudes of 100,000 feet and the sea to depths of 18,000 feet.
…The major purpose of BOMEX is to study the largely unknown mechanism of sea-air interaction, the primary process which drives the atmosphere’s circulation and weather systems. Until this process is understood, it will be impossible to make weather predictions good beyond a few days.
BOMEX director Joachim P. Kuettner describes the air-sea interface as the scene of a complex and continuous exchange of energy, water, gases, and particulates. Thus many of the 80 separate research projects in BOMEX will concentrate on measuring and studying the exchange of these and other variables such as momentum and electric charges, and on the ways that the atmosphere and the ocean transport such properties from the BOMEX area.
…Battelle scientists will investigate the transfer of particles from the stratosphere to the ocean and subsequent mixing in the ocean. To do this they’ll measure the concentrations of naturally occurring radionuclides, strontium-90 and other fission products, and some stable elements present in the air and sea.
Battelle-Northwest scientists H.G. Rieck, W.B. Silker, and D.E. Robertson (left to right) inspect high-volume filtration-sorption water sampling system for gathering radionuclides.
Beryllium-7—which cosmic rays constantly produce in the stratosphere— will be the primary tracer. By comparing beryllium-7 concentrations in the sea and air, together with weather information gathered at the same time, the Battelle scientists hope to learn more about air-to-sea transfer of small particles and their dispersion in the ocean.
The technique for ocean measurements involves a high-volume filtration-sorption water sampling system developed by Battelle. By pumping water from various depths through the system, minute amounts of radioisotopes can be collected. The Battelle effort will also involve measuring radioisotopes concentrations just above the ocean surface and at high altitudes.
After the filters from all samplers are flown back to AEC’s Pacific Northwest Laboratory in Richland, Wash., scintillation equipment will be used to count the beryllium-7 and other radionuclides, and neutron activation analysis will be employed to identify and measure stable elements.
From comparison of the beryllium-7 concentration in the air just above the sea with its concentration in water, the Battelle scientists can calculate its deposition rate. Under similar weather conditions this deposition rate can be used to predict the deposition and concentration of fission products in the ocean.
Brain Chemistry
Argonne Dedicates World’s Most Brilliant Source Of Hard X-rays: Research with bright, tightly focused X-rays at Advanced Photon Source will help resolve questions in materials science
“X-rays are light that lets you see down to the atomic scale,” says David E. Moncton, Argonne National Laboratory’s associate laboratory director for Advanced Photon Source. “In our case, the light is delivered in strobe fashion with a period of about 100 picoseconds. Our facility provides greater instrumental sophistication than other light sources and this enables us to see more complex structures faster and with smaller samples.”
Emission of synchrotron radiation is crudely analogous to the loss of velocity by a race car as it rounds a curve in the track. When charged particles are forced into a curved path, they emit radiation with the energy loss causing particle deceleration.
….In the realm of the chemical sciences, synchrotron radiation and lasers allow direct measurement of position and movements of atoms during chemical changes—the most basic information for chemical processes occurring in less than a billionth of a second. For example, pulsed APS beams are ideal for the study of photosynthesis. At the APS, a number of CATs will use a pump probe experiment in which a laser first excites the initiation of a photosynthetic reaction, then an X-ray pulse from the APS probes the reaction at various intervals following the laser pulse. The temporal evolution of interatomic bonds can be thus observed. The results, it’s hoped, will permit development of better photosynthetic systems to utilize solar energy.
-Joseph Haggin
Peter B. Medawar, in Advice to a Young Scientist, 1979
Science at EPA: Environmental Scientists Fault EPA For Its Shifting, Short-Term Research Focus
Rebecca L. Rawls
The issues facing EPA are growing more challenging, many of the environmental scientists noted. “The problems that the agency now faces are in large part the results of the more complex and subtle environmental problems we face,” M. Granger Morgan, head of the department of engineering and public policy at Carnegie Mellon University in Pittsburgh, says. “They don’t lend themselves to brute force command-and-control strategies. So developing new strategies—learning how to be more site specific, how to use common sense, how to learn from experience, how to be in a problem solving, rather than an adversarial mode—all of these are going to grow in importance if the agency is to stay healthy and successful.”
Says Raymond C. Loehr, a civil engineering professor at the University of Texas, Austin: “The problems were much easier to see back in the 1960s and 1970s. You could see fish dying or the Cuyahoga River burning, to take obvious examples. You could see the smog in Los Angeles. Everybody could see these things.” Now, he says, the environmental issues of concern to scientists are more subtle and less apparent to the public at large. “What the scientists tend to look at are signals that may not be very obvious to the public yet. The public sees dead fish; they don’t necessarily see that the population of certain kinds of fish are shifting, which may mean something else. They don’t see the things that might be happening in the atmosphere—like acid rain—that may cause an effect someplace else. … How do you get the public to understand when you say, ‘We’ve got problems in the oceans. We don’t know what they are, but we can see changes out there that look like they are things that people cause. We’ve got to look at that. That may be a bigger problem for the globe than anything else.’”
Acid Precipitation: The acidity of rain and snow falling on parts of the U.S. and Europe has been rising—for reasons that are still not entirely clear and with consequences that have yet to be well evaluated
Scientists Tackle Lunar Chemical History: Chemical analysis of lunar samples leads to model for comparison of element abundances in the earth and moon
DNA double helix, magnified 7.3 million times
Happy DNA Day! 60 years ago today, James Watson and Francis Crick first proposed the double-helical structure of DNA in Nature.
“Watson and Crick were right. Scientists have known that for some time, of course, but workers at the California Institute of Technology have now directly observed and photographed the double helix of DNA (deoxyribonucleic acid). Caltech graduate student Jack Griffith, who works with biology professor James Bonner, showed the electron micrograph to a meeting of the Biophysical Society in Los Angeles. At a magnification of 7,300,000 a portion of the long DNA molecule is clearly seen to be two separate strands helically wound about each other. They are clearly resolved and show a pitch of 34 Å.”
DNA Photographed
