September 24, 2017

Sure. I'd be very pleased to do so. A look at the Danish data for wind turbines is also...

...instructive though.

One needs to do a little Excel manipulation to do it, and be able to compare at utilize numbers, to see that this useless crap on average becomes landfill, on average, in about 15 years, meaning as with the case of the atmosphere, future generations will be screwed by our environmental wishful thinking.

The Danish Excel spreadsheets are here: Master Table of the Performance of Danish Wind Turbines

The much ballyhooed Danish wind program which inspired a lot of stupidity around the world, after strewing thousands upon thousands of leaky crap whirlygigs that depend on the disastrous lanthanide mines of Baotou, China, doesn't produce as much energy as a single nuclear plant built 30 years ago can produce.

Analysis of this data convinced me that my lack of hostility to the wind industry - which I may have held ten years ago - was inappropriate. The other thing that convinced me was the fact that we squandered a trillion bucks on this garbage in the last ten years alone (found here): Global "Investment" in so called "Renewable Energy".

A glance at the Mauna Loa carbon dioxide observatory might show what the environmental result of this massive squandering has done for climate change: Carbon Dioxide Trends at Mauna Loa

If one were to spend as much time with this data as I have over the last 20-30 years, one could see that a rate of 2.3 ppm per year, observed over the last ten years is the highest rate of decomposition of the atmosphere ever observed, meaning all the money squandered on so called "renewable energy" hasn't done shit even to slow the second derivative of the atmosphere's collapse.

Now, none of this is "peer reviewed;" it merely requires independent critical thinking to utilize.

This is also true of "peer reviewed" papers, with which I've spent the last 30 years reading about energy and the environment; it requires critical thinking as well.

This said, I'm happy to supply some links, some of which say that the environmental impact of the wind industry is inadequately evaluated, others suggesting what that impact is; and no, it's not zero, even ignoring the fact that the wind industry's main achievement is to increase rather than decrease reliance on unsustainable and frankly criminal dependence on dangerous natural gas.

Here's a nice current papers in the primary scientific literature which I have collected the full text from my files.

From very recent Chinese analysis of the wind portion of so called "renewable energy" (China faces the most health effects from the so called "renewable energy" scam:

Approach to Evaluate the Reliability of Offshore Wind Power Plants Considering Environmental Impact

Life cycle assessment and net energy analysis of offshore wind power systems (This one includes analysis of steel and concrete impacts, but is very weak on biological impacts.)

Bird Killer, Industrial Intruder or Clean Energy? Perceiving Risks to Ecosystem Services Due to an Offshore Wind Farm

Here's a whole book focusing on the biological implications on this stupid enthusiasm for this absurd and stupid scheme to fill the ocean and land with giant greasy tubines:

Wind Energy and Wildlife Interactions It was published just this year and it contains lots and lots and lots of "peer reviewed" references for anyone that's interested in the point. The text on the impact of German wind farms on the endangered red kites is illustrative.

Fuck the Kites; Wind Power is sexxxxxxxxxxyyyyyyyy.

One of the most moving references therein, is this one, a scientific paper written as a "plea." The catchment area of wind farms for European bats: A plea for international regulations

Fuck the bats; Wind Power is sexxxxxxxxxxyyyyyyyy.

This paper is open accessed:

Wind Farm Facilities in Germany Kill Noctule Bats from Near and Far

Turning to the marine area, on which tens of thousands of papers have been written, many in recent years, these scientists, mostly Marine Biologists complain that nobody has a clue about the effect of all this offshore development will have on the benthos, specifically those creatures that live on the sea floor, you know, like mussels: Turning off the DRIP (‘Data-rich, information-poor’) – rationalising monitoring with a focus on marine renewable energy developments and the benthos

Even though we have no idea at all about the effect of the useless and ineffective wind industry (at least with respect to climate change), there's lots of cheering here for a pop news article about mussels.

It's a disgrace.

By the way, I've spent the last 30 years using much of my free time reading the primary scientific literature about energy and the environment. When Carbonite reports on the number of files on my computer it has backed up, the number is usually over 600,000 files. I would guess that at least 50-60% of the papers in my files relate to energy and the environment, with a large portion of that devoted to climate change. This includes an extensive number of papers related to the world's safest, and most sustainable form of energy, nuclear energy, which the neither the wind industry or the solar industry can match for low environmental and human impact.

At the time I started this kind of time intensive obsession, right after Chernobyl blew up, I was, a fan of the wind industry and the solar industry, up to even ten years ago. I was, in 1986, much to my personal disgrace, a critic and opponent of the nuclear industry.

I've changed my mind.

It's not like I did so with inattention. Quite to the contrary, I've invested lots and lots and lots of time, and if nothing else, my opinions, my strong opinions are informed.

If you want "peer reviewed" stuff, one need not ask for it from a blogger on the internet. You can get it yourself. Google Scholar is your friend.

My conclusion after all this work is this: The wind industry and the solar industry are useless, and they are dangerous. I am embarrassed by the rote enthusiasm for these schemes on my end of the political spectrum, the left, the environmental left. The number of recs this vague, and frankly misleading news item generated here is troubling to say the least.

The solar industry in particular, which after half a century of wild cheering can't even produce 2 of the 570 exajoules of energy generated and consumed by humanity is nothing more than a modern day asbestos, asbestos having been a "wonder material" generating wide enthusiasm in the mid 20th century, only to be a bane for our generation to clean up - if we dare to clean it up.

The solar industry, which has already participated in causing 10% of the rice crop in Southern China to land above generally acceptable levels of safe cadmium, will prove for future generations, far more baleful, this after we also dumped trillions of tons of carbon dioxide into the atmosphere in which they must live. We assume, rather criminally, that they will do what we ourselves were incompetent to do; this is the real meaning of all this "by 2050, or by 2080, or by 2100" crap put out by assholes like the poorly educated bourgeois brats at say, Greenpeace. It's not going to happen; they are likely to live in a long running disaster movie and will lack the resources to help themselves. The planet will be a giant Puerto Rico, circa 2017.

Future generations may not forgive us; personally, I don't think they should. The lies we told ourselves will bare no expiation of our place in history, which may be recorded as the "worst generation. Ever."

Have a nice Sunday evening.

September 23, 2017

Trispecific Antibody to HIV Developed; May Represent A Real Cure for AIDS.

HIV, as many people know, is caused by a "retrovirus," that is a virus that does not contain DNA but rather RNA which is "reverse transcribed" into DNA in infected cells, whereupon the DNA activates machinery in order to construct new viral particles which ultimately rupture the cells, releasing more viruses.

The HIV virus thus offers two opportunities for transcription error: During transcription to DNA, and during formation of RNA for new viral particles. Moreover the HIV viral machinery contains no transcription error correcting mechanism. Mutations in HIV thus arise 10X faster than with DNA viruses.

It was my privilege to work, albeit in a peripheral sense, on the first several of the second class of anti-HIV drugs, the protease inhibitors in the mid 1990's; the first class was reverse transcriptase inhibitors like AZT. This class of drugs had a real impact on the disease; the survival of people like, for one case, Magic Johnson, is a testimony to their success.

The HIV protease cleaves viral zymogens, zymogens being proteins that are inactive until a part of each molecule cleaved by the protease, in this case an "aspartyl" protease that cleaves the zymogens at an aspartic acid residue, thus activating the viral proteins reverse transcriptase, integrase, and more of itself, the protease. Without this cleavage the viral proteins are inactive and the virus cannot function as a virus; it is inactivated, but not destroyed.

However, because of the rapidity of mutations in the virus, over ten billion viral particles are produced each day in an infected person with active AIDS, with a new generation of viruses being produced every 2.4 days at a rate of 140 generations per year, resistant strains of the virus can and do arise rapidly.

For the first generation of proteases developed in the 1990's, resistant strains had appeared for all of them by the year 2000.

The amino acid substitutions for the mutant strains to these drugs are listed here, where the letters refer to the codes for specific amino acids, and the numbers refer to the position in the HIV protease:

D30N: Nelfinavir. (Agouron/Pfizer).
M46I/I47V/I50V: Amprenavir (BMS).
L10R/M46I/L63P/V82T/I84V: Indinavir (Merck)
M46I/L63P/A71V/V82F/I84V: Ritinovir (Abbott).
Saquinavir: G48V/L90M (Roche)

The companies in the parentheses are the companies that developed these drugs.

(cf: Protein Science (2000) 9: 1898-1904)

Modern treatment for AIDS is not really curative; it is palliative and relies on a drug cocktail, a reverse transcriptase inhibitor (the class containing AZT), a protease inhibitor, and a third class, a CCR5 inhibitor known as a fusion inhibitor. It is hoped (and happily often observed) that the combination is effective, if expensive, with a failure to observe the regimen actually promoting the generation of resistant strains. (This is also true of other anti-infectives, such as antibiotics; however with antimicrobials such as antibiotics, the rate of evolution of resistant strains is slower.)

These drugs do not kill the virus; they inactivate it or in some (problematic) cases, slow its replication without actually halting it.

It is thus with some excitement that I came across this paper in the most recent issue of Science: Trispecific broadly neutralizing HIV antibodies mediate potent SHIV protection in macaques

(Xu, Pegu et al, Science 10.1126/science.aan8630: Final Page Numbers Not Yet Assigned) The paper was published by a consortium of scientists from the pharmaceutical company Sanofi, and a team of academic and government institutions, the latter type of institutions being under attack by the orange ignoramus in the White House and his fellow science hating enablers in Congress and his cabinet.

"Trispecific" means that the antibody has multiple "CDR's" or "Complementarity Determining Regions" designed to bind to different areas on cells. Antibodies are, of course, Y shaped proteins that mediate immune responses, and the CDR's are small sequences of amino acids in these proteins that recognize foreign or diseased cells and attach themselves to them result in their destruction or inactivation. Most antibodies are monospecific, designed to attack a single region of display on the foreign body. This protein, by contrast has been designed to simultaneous attack any of three different regions involved in HIV pathology; by doing so it reduces the avenues by which this wily virus can escape destruction and thrive.

From the introductory text of the paper:

Glycans are sugar signaling molecules bound to proteins. (They are very challenging molecules with which to work, although spectacular advances in the their characterization are under way.) "Epitope" is the sequence of amino acids that defines the CDR.

Some technical text relating to the design of the antibodies:



The molecule was able to prevent AIDS infections in a model animal, macques. This said, a molecule of this design has not been tested in humans, although human volunteers tolerated a bispecific analogue quite well. It is not known if the antibodies will not generate ADA's or "antidrug antibodies" which are antibodies against antibodies. This risk is always associated with protein drugs, despite their broad success in treating disease and saving lives.

The authors comment thusly:



The experimental details of the project are described in the supplementary information, which is apparently open sourced and is here: Supplementary Information

Here one may learn that the technology making this work possible is genetic engineering.

To wit:



All protein drugs are, in fact, GMO, and if you have a politically motivated hatred of genetic engineering and all things GMO because you get your "science" from reading Greenpeace pamphlets, Greenpeace being an organization that hates science with the same intensity as say, Republicans, these kinds of drugs are not for you.

Nevertheless, this is exciting and encouraging work.

Enjoy the weekend.

September 20, 2017

"Smart Bricks" for Measuring the State of Gasifier Walls.

It is becoming increasingly clear that all efforts to address climate change have failed, and it will fall to future generations - assuming that we have not permanently impoverished them and destroyed their futures with our bad thinking on energy and the environment, left and right - to clean up the mess with which we've left them.

In desultory reading on a night of reflection on my life where I feel the guilt of my generation, the history bad ideas in energy flows before me like a suddenly honest sinner's nightmare, but even as I recognize our crime against the future, I am forced to confess that not every bad idea is totally without merit if at least something valuable can be extracted from it.

One of the worst ideas in energy - one that has actually seen, happily only in a limited number of places, industrial application - was a pet project of Jimmy Carter, he of the bad ideas in energy. Briefly, at least while a Presidential primary candidate, though thankfully not when he actually became President, this bad idea was also endorsed, in theory at least, by Barack Obama. The bad idea to which I refer is, of course, coal gasification, technically known as "reformation" to make synthetic petroleum, also known as Fischer Tropsch fuels. (I opposed Obama in the 2008 primaries based on this position; happily he proved me wrong, his policies were much superior to his rhetoric in this case.)

In coal gasification, the idea is to heat coal to very high temperatures under pressure in the presence of steam - actually not steam but supercritical water - to make a mixture of hydrogen and carbon oxides known colloquially as "Syn gas." If the heat from this process is generated by burning coal and dumping the waste indiscriminately into the air, this technology would at best double, at worst more than triple, the climate change impact of petroleum, said climate impact already being entirely unacceptable.

Because we are not smart enough, or honest enough to even stop using fossil fuels, choosing to address them instead with worthless pablum about a grand "renewable energy" future that did not come, is not here, and will not come, the engineering challenge for future generations will dwarf ours, since they will need not only to ban fossil fuels, but will also remove the hundreds of billions of tons of dangerous fossil fuel waste, carbon dioxide, from the atmosphere, where it has been accumulating at a rate of over 30 billion tons per year, a rate which is rising, not falling, mostly because of the runaway popularity of the dangerous fossil fuel natural gas for which so called “renewable energy” is nothing more than a fig leaf. (Dangerous natural gas is not clean; it is not safe, and in spite of tiresome and obviously untrue nonsense put out by purveyors of the grotesquely failed and ridiculously expensive so called “renewable energy” scam, it is not “transitional.”)

Sophisticated arguments have been made that the thermodynamic and thus the related economic engineering challenges of removing carbon dioxide from the atmosphere make it next to impossible. A widely discussed paper on this topic is here:

Economic and energetic analysis of capturing CO2 from ambient air (House et al , PNAS.108 51 20428-20433.(2011)]

A number of arguments questioning this assumption have been advanced and, in the very same journal where the House paper was published, a team of scientists at Columbia has argued in an overview paper that House's paper better not be the last word because removing the dangerous fossil fuel waste carbon dioxide is an urgent matter: The urgency of the development of CO2 capture from ambient air (Lackner et al, PNAS 109 13156–13162 (2012)) Of course, this paper was published, as of this writing, almost 5 years ago, so whatever “urgency” there is about climate change, it’s been totally ignored, which is not to say it's really not urgent, only that it's becoming more urgent.

For a nice review of chemical air capture strategies see: Direct Capture of CO2 from Ambient Air (Jones et al Chem. Rev., 2016, 116 (19), pp 11840–11876) (I've attended lectures by the primary author of this review, Chris Jones, of Georgia Tech, at scientific meetings; I'm impressed by his work.)

From my perspective, air capture should be an achievable goal for human beings in a generation less stupid and selfish than ours. I say this only because clearly plants do this (albeit surprisingly inefficiently in energy to mass ratio terms) and therefore, just as generations of human beings living before the Wright brothers recognized that heavier than air flight had to be possible, since birds and insects existed. House's paper explicitly states that biological strategies for removing carbon dioxide are not covered.

There is, of course, an option that simultaneously exploits both biological and physicochemical options for removing carbon dioxide from the atmosphere, and utilizes chemistry that I evoked at the outset of this post, reformation, not of coal, but of biomass. The combustion of biomass has been, or course, practiced for millennia, and it is still practiced widely today; but as practiced it is very dangerous, dangerous biomass waste is responsible for about half of the seven million air pollution deaths that take place each year as of 2017, even as awful poorly educated dullards carry on about so called “nuclear waste,” which has killed no one in more a half a century of accumulation, and which is in actuality a valuable resource that future generations may appreciate more than most people in this entirely easily distracted generation are competent to understand.

No matter.

My hostility to so called “renewable energy” should be familiar to anyone familiar with my writings here and elsewhere, and biomass is often defined as “renewable energy” but, this said, I believe, as I do for so called “nuclear waste,” that biomass waste has great potential as a resource, most notably for the removal of carbon dioxide from the atmosphere, but also for the recovery of other critical materials, the most important of which is phosphorous. (World supplies of mineable phosphorous – on which the world’s food supply currently depends – are very much subject to depletion.)

While “renewable” biofuels like ethanol have represented a tremendous environmental tragedy in the United States, (you know, the road to hell…) resulting in the destruction of the Mississippi Delta ecosystem, for example, it happens that there is another approach to biomass utilization that is likely to prove far more benign than fermentation and distillation, and to the extent it is one of the few options capable of actually removing carbon dioxide from the air, deserves consideration. This is the thermal reformation of biomass, where biomass substitutes for the coal based scheme that Jimmy Carter proposed, and which frankly, we should all be grateful, never made it to big time in the United States, the world’s most egregious consumer nation.

If the heat for driving this largely endothermic reaction is nuclear heat, the process is almost certain to be unambiguously carbon negative, particular in the case where the carbon collected is utilized in products like polymers, carbon fibers, carbon nanotubes, refractory metal carbides (which would be necessary for nuclear heat at high enough temperatures to drive reformation reactions and thermochemical water splitting reactions), silicon carbides and extremely useful and exciting graphene, modified graphene and carbon nitrides. All of these products sequester carbon, and do so in an economically viable way, a “waste to products” way.

But there’s a problem. Biomass is not pure carbon, hydrogen, oxygen and nitrogen, of course: It also contains a considerable fraction of metals. The most problematic of these are the alkali metals, in particular potassium and sodium, and to a far lesser extent, lithium and rubidium.

Consider potassium.

A nice paper, the residue of Chinese grammar in the translation aside, which was recently released as a corrected proof discusses the case quite well: Transformation and release of potassium during fixed-bed pyrolysis of biomass (Lei Deng Jiaming Ye Xi Jin Defu Che, Journal of the Energy Institute, Corrected Proof, Accessed 9/19/17)

An excerpt:

A form of energy technology which requires constant replacement of infrastructure is neither sustainable nor environmentally benign, simply from a materials utilization standpoint, since the preparation of materials is generally energy intensive. (This is a big problem with another example of the failed expensive so called "renewable energy" industry, the wind industry, where Danish database of turbines shows that the piece of crap turbines don't last an average of 16 years before needing replacement.)

I personally believe that the materials science issues involved of high pressure reformers is one that can be solved; however the question stands unequivocally before us that we are out of time, that anything we may or may not do to address climate change is already too late. It may be desirable therefore to build less than optimized biomass reformers, at least as a stopgap measure, until engineers and scientists can optimize materials to be more sustainable. We must have technologies that not only prevent the dumping of dangerous fossil fuel waste into our favorite waste dump, the planetary atmosphere, but also remediate the waste dump itself: Our atmosphere is a "superfund" site, and we must find a way to clean it.

It is therefore with interest that I read a recently published paper that purports to have developed a technology that can at least measure the performance of materials in high temperature reformers continuously, during operation.

The paper is here: Estimations of Gasifier Wall Temperature and Extent of Slag Penetration Using a Refractory Brick with Embedded Sensors (Debangsu Bhattacharyya, et alInd. Eng. Chem. Res., 2017, 56 (35), pp 9858–9867)

Some text from the paper:



"Almost two years..." That's even worse than wind turbines, and wind turbines suck. Moreover, the liner they're describing is chromia. Chromium is not an environmentally benign element with which to work. (To be fair there are many other refractory oxides, carbides and nitrides with which one can envision accomplishing the same task, one of the most important of these is zirconia, ZrO2, and of course nitrides, like, say, thorium nitride.

The authors go on in the paper to describe a type of brick with an embedded sensor. The brick is alumina and in it is embedded a thermoresistor made of tungsten carbide in an alumina matrix.

The sensor is arranged so as to give an interdigital capacitor, a set of capacitors in series that measure changes in temperature via changes in the diaelectric constant of the system and thermal expansion resulting in changes in distance between the capacitor as well as changes in the diaelectric constant (presumably from a base line) owing to the intrusion of slag elements.

Some remarks from the conclusion:



One wishes the authors luck in a country, this one, where the three branches of government are controlled by people who hate science because they're too stupid to know any.

I appreciate the work of Dr. Debangsu Bhattacharyya, as well as his courage to bear his very cool name right in the heart of Trump country, West Virginia.

Interesting work.

Enjoy the rest of the work week.

September 16, 2017

A Polly Arnold Review on the Organometallic Chemistry of Neptunium.

There's this great video by Norah Jones during a tribute to Graham Parsons where in preface to performing his song "She" she declares that on listening to every song performed at the tribute she said, "Oh that's my favorite song..." and then declares that "But this is really my favorite song..." (It's a wonderful performance.)

My kid, who I am happy to report is visiting me this weekend - coming home from college to celebrate my birthday - always laughs at me because every time I see a poster on a wall in a university building referring to the chemistry of element - any element - I say "That's my favorite element..."

"Dad," he says, "Every element is your favorite element." (That's not true. I don't care all that much about the chemistry of terbium, or for that matter lutetium.)

One of my favorite elements, really, is the element neptunium, since I regard it as a key to decreasing the risk of nuclear war as close to zero as is possible, via the "Kessler Solution." (We cannot uninvent nuclear weapons, nor can we ever eliminate the risk of nuclear war, since the supply of uranium is inexhaustible. I explored this point elsewhere: On Plutonium, Nuclear War, and Nuclear Peace

In another post on the same website I wrote about some interesting chemistry associated with the actinide elements, noting that the Nobel Laureate who had, in many ways, the greatest effect on day to day life of any Nobel Laureate, Fritz Haber, since despite its greatly problematic environmental consequences, the world's food supply depends on the Haber process, noted very early on that uranium was likely to be wonderful catalyst for nitrogen fixation: Uranium Catalysts for the Reduction and/or Chemical Coupling of Carbon Dioxide, Carbon Monoxide, and Nitrogen. In that post, I discussed the work of Polly Arnold, a world leader in organoactinide chemistry.

Now Dr. Arnold has written a review article in one of my favorite journals, Chemical Reviews:

Organometallic Neptunium Chemistry (Chem. Rev., 2017, 117 (17), pp 11460–11475)

An excerpt from the text:



The density of neptunium, is, by the way, 19.5 tons per cubic meter, meaning that all the neptunium produced each year would fit into a cube 130 centimeters on a side. (This compares favorably with dangerous fossil fuel waste which at 30 billion tons per year, can never be contained under any circumstances.) However no one could ever construct such a cube, since 19.5 tons of neptunium greatly exceeds its critical mass, and this being true, the element is a very wonderful potential nuclear fuel.

50 tons of neptunium is a very valuable resource, especially because of the very interesting property metallic neptunium has of forming a low melting eutectic with metallic plutonium that makes for interesting possibilities for the LAMPRE type reactors that were explored by a generation smarter than ours, in the mid twentieth century.

One hopes that a future generation, smarter than ours, will utilize this neptunium resource to clean up the intractable mess with which our irresponsibility and dumb assed ideas and fantasies has left them.

They may not, and should not, I think, forgive us.

Chemical Reviews, as an aside, is a wonderful place for chemists to catch up in areas in which they are non-specialists. I love that journal.

Enjoy the rest of the weekend.

September 15, 2017

Oh oh. A plutonium powered satellite hit the atmosphere and the SNAP device vaporized.

As the beautiful Cassini mission comes to an end, I am reminded that television physicist with a cool hair cut, Michio Kaku, opposed the mission, since he was concerned it would crash into the earth, the plutonium RTG - the same kind of device that ironically went to, um, Pluto (for which the element is named) - and wipe out all life on Earth.

And Michio Kaku would know, since he's a famous physicist who appears on TV all the time.

And, now, I have the unpleasant duty to inform you that the very event he feared has happened, and has been reported in a major scientific journal; be scared; very scared.

Here's the report: Atmospheric Burnup of a Plutonium-238 Generator (P. W. Krey, Science 158 (3802), 769-771 1967)

Excerpts from the text:

Now the bad news:



I conclude we're all going to die.

As for Michio Kaku, I have had occasion to watch him on TV. He has a very cool haircut and it makes his kind of slightly supercilious lectures a little bit more tolerable. I can't say I've watched a lot of his shows, but he certainly does seem to know something about stars and stardom.

But again, I haven't watched him too much. I'm not all that much into television physicists.

I will say this. Scrolling ten minutes through Cassini pictures is, for me at least, worth a lifetime of Michio Kaku television appearances.

Just this morning I was reminding of reading, a few years back, Jared Diamond's fabulous book, COLLAPSE: HOW SOCIETIES CHOOSE TO FAIL OR SUCCEED

In it he tells the story of the demise of the Greenland Norse, who he concludes died out because unlike the Inuit, who survived quite well in exactly the same region, even further North than the Norse, the Greenland Norse had some kind of cultural prohibition, a CULT prohibition perhaps, against eating Salmon.

This he concludes from the presence or absence of salmon bones in archaeological sites related to the two cultures. The Norse, he claims, would only eat grain and grain fed domestic animals, and died out, when the temporary warm spell that brought them to Greenland ended. The Inuit lived, eating Salmon, just as they had done for thousands of years.

This is actually relevant to the issue of plutonium burning up in the atmosphere in 1964. (Actually metric ton quantities of it were vaporized in nuclear testing before the SNAP9A plutonium RTG vaporized, but it was generally the 239-isotope and not the more radioactive 238 isotope that powers spacecraft.)

Our atmosphere is collapsing, more rapidly than ever before. We have a cult of so called "renewable energy" to address it, and we've spent trillions of dollars on this cult in just the last ten years, with the result that the rate of the collapse of the atmosphere is increasing, not decreasing.

It has been shown that in the last half a century, the fuel that displaced the most dangerous fossil fuels was nuclear fuel, including a healthy amount of plutonium. There are more than sixty billion tons of carbon dioxide that didn't get dumped into the atmosphere because of plutonium and uranium.

We, however fear plutonium just like the Norse apparently feared Salmon.

Diamond's right; societies choose to fail, apparently in the 21st century, it's all one society, spread across the planet.

And we are failing. In the next two weeks or so, we will reach the annual minimum for the sinusoidal seasonal variation in carbon dioxide atmospheric concentrations. It will come in at above 403 ppm. Ten years ago, the time at which our two trillion dollar expenditure on wildly popular so called "renewable energy" started, it was 381 ppm.

We'd all like to believe that all the responsibility for climate change resides on the right. But just as Lincoln blamed slavery on the South and the North in his 2nd Inaugural address, we on the left have our own guilt in the issue of climate change.

I personally think we should eat the salmon, but I predict we won't.

I'm sorry for this post, but I stumbled across this old paper while researching modern thermoelectric materials, a fascinating subject, and I just couldn't resist this note.

Have a wonderful Friday tomorrow and a wonderful weekend.

September 13, 2017

North Dakota.

September 6, 2017

My Favorite Things

September 4, 2017

Computational Screening of 670,000 Materials For Optimal Separation of Krypton From Xenon.

As I poke around this long weekend through scientific papers that I was inspired to collect but never actually read and filed properly I came across a really cool one, this one: What Are the Best Materials To Separate a Xenon/Krypton Mixture?

(Cory M. Simon†, Rocio Mercado‡, Sondre K. Schnell†§, Berend Smit†?, and Maciej Haranczyk*¶ Chem. Mater., 2015, 27 (12), pp 4459–4475)

Xenon and Krypton are very rare gases in the Earth's atmosphere, from which they are obtained industrially, because they are very useful, at considerable expense. (The most common use for xenon is in automotive headlights because its excited states decay to produce light that is very similar to daylight.)

The authors of the cited paper do quite a nice job in describing some of the background on these two gases, and I'll quote what they say in their introduction:

The noble gases xenon (Xe) and krypton (Kr) have several important applications.28 Xenon is used as an anesthetic 29?31 and for imaging 32 in the health industry and as a satellite propellant in the space industry.33 Both xenon and krypton are used in lighting,34 in lasers,35,36 in double glazing for insulation,37,38 and as carrier gases in analytical chemistry.39 Since krypton and xenon are present in Earth’s atmosphere at concentrations of 1.14 and 0.087 ppm, respectively,40 the conventional method to obtain xenon and krypton is as a byproduct of the separation of air into oxygen and nitrogen by cryogenic distillation.41 This byproduct stream from air separation consists of 80% krypton and 20% xenon.42 At Air Liquide, this mixture is compressed to 200 bar and stored in cylinders, then sent to a separate Xe?Kr separation plant to undergo another cryogenic distillation to obtain pure xenon and pure krypton.43 Cryogenic distillation for the separation of krypton and xenon has a very high energy and capital requirement, reflected by the cost of high-purity xenon, about $5000/kg.44

Both gases are considered in general general to be inert, and until 1962 they were thought not to exhibit any kind of chemistry at all. Since that time, it has been discovered that both gases can, in fact, react to form compounds, krypton only at very low temperatures. The chemistry of xenon, by contrast, is quite extensive. (I touched briefly on the discovery of xenon chemistry here: Neil Bartlett's superpowerful oxidants NiF6- and AgF4- and the preparation of RhF6.)

As noted by the authors, the separation of these two gases is energetically and economically expensive, and the purpose of their paper is to examine, by computer modeling, approaches to designing materials that can reduce the costs of their separation by a technique known as "pressure swing absorption," PSA which relies on a process in which a gas consisting of multiple components is pressured in a chamber in the presence of a solid material that has a capability to absorb one component in preference to another. (Home oxygen generators for medical use, and nitrogen generators in some scientific laboratories utilize a PSA approach to separate these bulk gases.)

It is possible to exploit, I suppose, the chemical differences between the gases to effect their separation, however in most cases the chemistry involves the use of highly reactive, corrosive and toxic fluorine gas. In the presence of water, xenon fluorides can hydrolyze to form xenon oxides which can be highly explosive.

By contrast, pressure swing absorption is orders of magnitude safer and most probably considerably cheaper.

Modern computers are extremely powerful compared with computers from even a short time ago, but computational power is not necessarily cheap or free when one considers very, very, very complex calculations.

Nevertheless in silico calculations can save far greater expense in screening for molecular structures - be they involved in medicinal chemistry or in materials chemistry, such as being explored here - that accomplish these kinds of tasks.

Candidate materials for the separation of these gases exist in quite an array of differing types, again, I'll let the authors describe them:



The separations, as the author's note, in a pressure swing situation rely mostly on the size difference between the two types of atoms: The mean diameter of a xenon atom is 198.5 picometers, of krypton 183 picometers, a small, but significant difference. The idea is to structure the pores in materials so that xenon cannot fit into the pores while krypton can, or conversely that krypton can easily diffuse out of the pores while xenon can do so only slowly. Besides size, differences in their electronic structure - which accounts for the differences in their chemistry - can also be exploited without actual chemical reactions taking place.

Their computational approach, which they describe as considerably streamlined in terms of the computational algorithms utilized previously for one class of possible absorbents, metal organic frameworks (MOF), the previous approach being described as "brute force" is described in the following text:



The authors in this screening process describe two known materials which may be useful in these separations:



This paper has been cited extensively since its publication two years ago, and it might be fun, if I find the time once my favorite academic libraries reopen after the holidays, to look into these citations to see if these predictions have been experimentally confirmed.

It is interesting to note that isotopic ratios of these gases tell us a lot about the history of this planet, owing to the fact that actinide elements, for example, long lived plutonium-244 - which is known to have been a constituent of the early Earth (because of xenon isotopes) - spontaneously fission in a characteristic way that causes a traceable signature of geological history.

(See for example: Xenon isotope constraints on the thermal evolution of the early Earth (Nicolas Coltice a,⁎, Bernard Marty b, Reika Yokochi c, Chemical Geology 266 (2009) 4–9))

As the authors of the original paper note, these separations would also be valuable in the processing of used nuclear fuels, because both elements are fission products. No radioactive isotopes of xenon are very long lived in nuclear fuels; they rapidly decay into other isotopes. Xenon-135 has the highest neutron capture cross section of any nuclide known, it is rapidly converted into non-radioactive xenon-136 in the neutron flux in the core of nuclear reactors. Because of this, it does not accumulate, and in any case its half life is on the order of hours, not days. (The presence of xenon-135 in reactor cores where it is the cause of an effect known as "xenon poisoning" played a role in the very stupid decisions made by the operators of the Chernobyl reactor that exploded: Their decisions, made late at night, to remove the control rods from the reactor was intended to overcome xenon poisoning effects.)

Fission gases contained in fuel rods are therefore highly enriched in these valuable gases, and in theory they could be collected from used nuclear fuel for use, especially xenon.

Krypton contains one relatively long lived radioactive isotope, krypton-85, and its detection has been utilized to identify nuclear explosions (both atmospheric and underground) as well as reprocessing of nuclear fuels around the world, since it is generally vented to the atmosphere rather than recovered for use. (Radiokrypton-85 I think is possibly a very useful material for providing a continuous portable light source for remote locations or as a continuous power source.) Venting it to the atmosphere is probably not a very dangerous practice however, certainly not at the level of venting dangerous fossil fuel waste to the atmosphere, since dangerous fossil fuel waste and dangerous biomass combustion waste combine to cause 7 million deaths every year.

Krypton 85 can also be stored to provide a source of non-radioactive rubidium-85 which would be less radioactive than natural rubidium, since the latter contains the naturally occurring long lived radioactive isotope rubidium-87. However, except for esoteric research purposes, I cannot imagine that there is much call for isotopically pure rubidium-85, but hey, you never know.

Some folks might find all of this stuff as interesting as I do.

Enjoy the rest of the labor day weekend.

September 3, 2017

Trump Administration Announces New $20 Bill Design Honoring Harriet Tubmans Owners

The Trumpist $20 bill

September 2, 2017

Nature: Cassini's 13 Years of Stunning Saturn Science - in Pictures.

Cassini’s 13 years of stunning Saturn science — in pictures

It's brief, but opened sourced; I recommend taking a look at the PDF version.

I love this graphic:

http://www.nature.com/polopoly_fs/7.46007.1504091141!/image/casinis-journey.jpg_gen/derivatives/landscape_630/casinis-journey.jpg

The mission was launched 20 years ago, in 1997. The world seemed so full of hope then; Bill Clinton was President, and even though that racist freak Newt Gingrich was in control of the House of Representatives, it seemed like the country was on the right track in spite of his ignorance now matched by other racists, Paul Ryan and the worst racist in the Senate, Mitch McConnell.

These creeps would have never funded science like this.

No one thought, in 1997, especially not me, that the entire country would be controlled by Neo Nazis who hated science, but here, 20 years later we face this.

The United States was a great nation in 1997; a nation that could launch the Cassini mission. It is terrible how far we have fallen in so short a time.

Let us hope and work to make it that kind of nation again, not a nation of Klansmen, but a great nation that can do things like Cassini. Let this not be the last outstanding space science and engineering to come from our country!