The health condition of the Fukushima Children in Ginza, Tokyo .

Dear Reader,

I saw this film recently, it makes some claims that the Fukushima reactor accident is making children sick. I think that this film raises some interesting points.

Appeal concerning the health condition of the Fukushima Children in Ginza, Tokyo ..

There is a problem, if the above average level of radiation in Japan is able to make children ill then why is Ramsar in Iran not famous for ill children ? In this place in one year the background radiation dose is normally more than 100 mSv.

In Japan it has been decided that if the dose rate is greater than 20 mSv that people will be relocated, so the people in Ramsar should be more ill than the general public in Japan near the Fukushima reactor accident site.

One of the people in the film had to go for a CT scan, I would like to know if anyone has considered how this is likely to have involved quite a large X-ray dose. While people get concerned about an exposure from a reactor accident, many people do not seem to be as concerned about medical exposure (due mostly to X-ray radiography). This is something which I can never understand.

Also if the children of Fukushima were being exposed to so much radiation that they feel ill as a result (chronic radiation syndrome ?) then I imagine that their blood counts would be rather abnormal. If for argument’s sake they were so strongly exposed then blood samples from them would show signs of radiation exposure.

For a large dose, I would expect cell counts to be abnormal. At lower doses I would expect a much higher number of chromosomal abnormalities per litre of blood. If someone can bring us this type of evidence then I will believe that the children of Fukushima have been exposed to a lot of radiation, but until I am presented with such evidence I will remain very suspicious of the claims of these radiation related illnesses. The thing is that to induce the non cancer effects which appear shortly after a radiation exposure a very large dose is required, and the dose must be above a threshold. Below the threshold the effects can never be seen.

It is a bit like alcohol, humans and drunkenness. To get a person drunk requires alcohol, the more alcohol you feed them the worse the drunkenness becomes. Below the threshold dose it is impossible to get the effect of drunkenness, for example if 200 people take communion at a church and have a tiny sip of wine then non of them will come out of the church as crazed drunks (Unless they were drunks before the service). I hold the view that as a result of Fukushima that no member of the general public has had a radiation dose which is able to cause one of the deterministic effects which appear shortly after the radiation dose is delivered to a human.

Even after the much worse Chernobyl accident no members of the public were stricken with the deterministic effects of radiation (radiation sickness), so I would suggest that my readers take care when they here of claims from Japan about the radiation making children feel ill. We need to have a respect for the truth, part of a respect for the truth is to resist telling lies or making exaggerations even if you think (or know) that the thing you want to warn people against is very bad. One of my roles at Chalmers has been to help supervise research on serious nuclear accidents, I can tell you that serious nuclear accidents are thankfully rare but they can be horrible even without inventing new effects or exaggerating the effects.

Muons and Fukushima

Dear Reader,

One of the great problems right now is working out where the fuel in the damaged cores and the ponds is, and in what condition the fuel is in. We can take for granted that the fuel which was in units 1, 2 and 3 has been damaged by overheating. But the state of the fuel in the ponds was a bit more of a mystery to us.

After clearing the rubbish out of the pond at unit three it has been possible to inspect the pond, the pond is frankly in a bit of a mess. But the fuel seems to have escaped serious damage. Photographs have been taken of the fuel racks in the pond and it does not look like there has been been any dire melting or explosions in the pond.

I have seen that some samples have been taken from the pond at unit four to allow them to be examined (these were samples of unused fuel which were being stored in the pond at the time of the accident). The work so far suggests that the fuel in the pond is in good condition. This suggests strongly that no nuclear explosion occurred in the pond.

The other great question is the state of the reactors. I saw something interesting recently, it is a sensing system based on cosmic rays (muons). This looks to me like a good method for finding the fuel inside the damaged reactors without having to get up close and personal with the stricken reactors.

Another thing which needs to be done is for society to recover from the accident, I have seen some advice from the IAEA on the subject of remediation of the contaminated land (outside the nuclear reactor park). This document might be of interest to some of my readers. It includes a discussion of the cleaning of different types of areas which include farmland. As I predicted it does include the question of deep ploughing the land.

BNCT a great way to cure cancer

Dear Reader,

Recently I looked into the core of a nuclear reactor for the first time in my life, the closest I had been before then was looking through the door in the inner shielding at the top cap of a defunct reactor which had been shut down decades ago.

I was standing in the operating position above the water pool of a 250 kW reactor which is used for research, training and for treating cancer; the reactor was not running while I was visiting. Apparently in that location the dose rate is about 400 microsievert per hour when the reactor is running, while this dose rate is no where near the level which would cause an injury or death. As the 1970s LD₅₀ dose for radiation was about 3.5 grays, it would take 8750 hours there to reach this dose. The 365 days required to get this dose would mean that the self repair mechanisms in my body would reduce the baneful effect on my body. I do not think that it would make me fall down dead, but within a week or so I would be hitting my yearly limit, so that I would not want to linger in that spot while the reactor is running.

It was an interesting view looking down through a 6 meter pool of water at the core of the reactor; this reactor is a type which is not designed to make electric power. Instead it is designed to make neutrons for radioisotope production, for training and for the treatment of cancer. Almost twenty years ago the reactor was modified to allow it to be used as a neutron source for the treatment of cancer by the boron capture method.

Now I know that some elements in society are very antinuclear but I would ask even the most antinuclear people to stop, read this and think for a while. Frankly I would like it if you shared my point of view but even if you do not come away from reading this with my point of view I accept that people are free to choose what they like to believe.

Now if you have the misfortune to get cancer then one of the treatment methods is radiation, now the problem is that it is best to give the cancer cells one heck of a going over with one almighty dose of radiation while only giving the healthy tissue a very small dose. This is the ideal but sadly with many radiation treatments it is not quite possible to do this.

The most common method seems to be either X-rays or gamma rays delivered from a source outside the patient. The problem with these treatments is that the beam of radiation damages all tissue that it passes through. One solution to try to spare the healthy tissue is to aim beams of radiation into the person from different angles so that the paths of all the different directions converge on the spot where the nasty tumour is. This is not a perfect way of doing things, no matter how good the radiation expert is they will damage some healthy tissue.

The next step up in controlled and localised dose is to implant a source into the person; it is possible to implant a small but intensely radioactive source right at the spot where the cancer is. This can be used to treat a range of different cancers which include cancer of the cervix, breast and prostate. As radiation obeys an inverse square law this treatment is often very good at sparing the healthy tissues.

If you double the distance from the source you make the dose four times lower, while if you triple the distance from the source then the dose is nine times smaller. I hope that you can now see that the effect should be very well localised in one part of the body. With the right choice of photon and beta particle energy you can make the dose even shorter ranged thus allowing you to wipe the smile off the cancer’s ugly face, send it away with its tail between its legs while leaving the vast majority of the person undamaged.

Sounds great doesn’t it! But there is a fly in the ointment. Today for some applications some of the greens are yelling that we need to stop using nuclear reactors. The problem is that for the generation of the radioactive sources often the only thing which will do the job is a nuclear reactor which has been optimised for a high neutron flux. To do this you need to make the core nice and compact and run the reactor with a highly enriched fuel. Here is one of the best arguments for keeping radioisotope production reactors, while they might not fit in with some people’s idea of what is green they do provide an affordable and reliable supply of lifesaving diagnostic and curative medical products.

Now some people might be yelling at the screen that we should ditch the old fashioned radioactive sources for medical use and use modern particle accelerators like LINACs. I would like to point out that the treatment systems based on radioactive sources are simpler and there is much less to go wrong. Using no more than a sheet of graph paper it is possible to predict the strength of a radioactive source on day X, while accelerators are more complex. I am aware of radiotherapy accidents in both Poland and the USA where accelerators have failed to behave as expected. Both cases caused some ugly overexposures of people.

Also to deliver the radiation just where it is needed to some where like the cervix or the prostrate it is not possible to do it with a typical medical accelerator. The way that the LINACs typically work is by whipping up electrons to very high speeds and then slamming them into a metal target. The change in velocity (deceleration) of the electrons cause them to emit very high energy gamma rays. An alternative second method is to use a gadget called a betatron. Both the betatron and the LINAC are suitable as replacements for the cobalt-60 based teletheraphy units which used radioactive sources to make beams of gamma rays, but they are not able to replace the treatments based on radioactive sources which are placed right in the tumours.

Now while brachytherapy is all very well, there is something even better. One of the problems with cancer is the oxygen effect. If tissue is nice and well oxygenated then low LET radiation like gamma and X-rays are good at causing harm. But when the tissue is poorly oxygenated then it has much less effect. While the surface layers of a tumour are often well oxygenated, the core of a tumour is often poorly oxygenated. What can happen is that when a tumour is given a dose of radiation the inner less oxygenated cells survive and then continue to grow thus making the tumour reappear.

But a high LET radiation such as alpha particles still works even if the oxygen content of the tissue is low. If boron is subjected to neutron bombardment then it forms alpha particles which are able to then do immense damage to the cancer while leaving the healthy tissue alone. The reason that this works is that the person is given a dose of a boron containing drug which mainly absorbs into the cancer cells. The drug used in Finland for this treatment is L-para-Boronophenylalanine, this is an amino acid bearing a B(OH)₂ group.

The boron-10 reacts with the neutrons to form alpha particles and lithium-7.

¹⁰B + n → ⁴He + ⁵Li

The helium and lithium-7 ions then damage the cancer cells, as the boron concentration in the healthy cells are low the healthy tissue gets a far lower dose. Here is a picture of the boron compound which is used for the treatment.

A molecule of the amino acid which bears the B(OH)2 group required for the BNCT

Now some of those of you reading this blog might not be the greatest enthusiasts of the nuclear sector, but I would like to caution the “antinuclear brigade” against throwing the baby out with the bath water.

While I am well aware that it is possible to make bombs using some nuclear technology, I would like to point out that Patrick Moore pointed out that the fact that car bombs made with ANFO (Ammonium Nitrate Fuel Oil) are bad. Frankly I have to say I strongly agree that ANFO based car bombs are perfectly horrible.

But he wrote that the fact that you can make a nasty large bomb out of a car, some ammonium nitrate fertilizer and some diesel fuel is not a good reason to ban any of these three items.

I would like to also point out that the nuclear equipment in the form of a radiotherapy reactor is not in a form which is suitable for use as a weapon, I think that the only weapon I had access to at the reactor site were some lead bricks in the radiochemical lab and the bright yellow extra long tongs. I think I can get some weapons which are more suitable for mindless violence from a typical garden centre !

I have to explain something to you, it is possible to use many objects as weapons but the fact that it is possible to employ or adapt an object into a weapon is never a valid reason for banning an object. I will give you an example, in Mr Archer’s prison diary it explains how one person once took a toilet brush, they cut off the bristles and then sharpened it into a sword. The fact that someone managed to adapt a toilet brush into a sword should not be used as an excuse to ban the things !

The right to roam into a nuclear site ?

Dear Reader,

It has come to my attention that some tourists have been indulging in some outdoor activities which sadly have got them into trouble. Now for those of you who have not lived in Sweden, I need to tell you about the general right to go anywhere in the country side. Unlike the UK any person in Sweden can go for a walk anywhere in the country side, this is known as allemansrätten which even gives you the right to take wild fruit from land which you do not own.

However the allemansrätten is not a license to do as you like in the country side, for example I can not pitch my tent in next door’s garden. One of the key ideas behind the way in which people in Sweden behave when using the allemansrätten rights is the idea that you should not damage anything or disrupt the lawful activities of the landowner or another person. For example I should not trample over a field of wheat and disrupt the farmer’s crop growing by walking all over his/her plants.

I would also like to point out that some sites are restricted places which the allemansrätten does not apply to, for example the vault at a bank is not a place I can just stroll in and out of, also the King’s palace is a place which is restricted and also nuclear sites are restricted. A less grand place which is also restricted is next door’s kitchen, the allemansrätten does not allow me to gather frozen berries from their freezer, nor does it allow me to go rock climbing on their roof.

I have read that some of these nature walkers have been using ladders to bypass some fences at a outdoor leisure site in the east of Sweden, sadly they choose the wrong site. I also note that a simple ladder does not give you a good view of nature or a very challenging climb. I would like to respectfully suggest in future that these nature walkers sign up for a session of via ferrata, rock climbing or perhaps they should just go hill walking in the lake district.

The ladder is too easy a thing to climb and it is unlikely to give a person much of a feeling of satisfaction, I suggest that a tree, climbing wall or rockface would be better.

While doing via ferrata, rock climbing or hill walking does provide you with a very enjoyable view, sadly going over the fence at Forsmark park does attract the attentions of the boys in blue. I have heard that the climbers are to appear before the beak to explain themselves. I think that their deeds are somewhat more serious than sneaking onto a via ferrata route without paying. I have to agree with the sentiment expressed at “Nuclear Power yes Please” that the best way to visit this park is to phone up and ask them to let you in via the front door rather than risking damaging your clothing while climbing the fence.

I would be interested to know what these nature walkers have done with their ladders after their trip to the park, I could always do with an extra ladder for working on fruit trees or the side of my house.

Another group of nature walkers have also misunderstood the allemansrätten rules at a park south of Sweden, this park is a seaside site which commands impressive views of the sea. Here the nature walkers were using metal work tools on the fence. I think that they have very much misunderstood the right and wrong place to do some recreational metal work. If you want to do some modern art using metal work tools or some other recreational metal work, I suggest that you buy metal work tools from the wonderful choice at the Swedish hardware shops and the go home and try some amateur blacksmithing or for those with a more down to earth point of view then perhaps you could do some DIY home repairs or improvements.

On a more serious note, I would like to know if the Greenpeace people are trying to commit “suicide by cop”. The core thesis in the “suicide by cop” is that a person does something which causes a police officer (or another person) to fear for his life (or the lives of others) then the police officer then uses deadly force to stop the person. Thus the person (who was unable or unwilling to kill themselves) gets to commit suicide by proxy. I think it is only a matter of time before a greenpeace activist is seriously injured or killed during an illegal entry into a nuclear site, I think it is time for greenpeace to call time on this irresponsible behaviour.

Now those of you who are greenpeace members or even activists who are reading this, I have something to say to you. I care for the environment, but I insist on truth and responsibility. While some of what greenpeace has done (like saving the whales) I strongly agree with, the antinuclear campaigning (and the antichlorine campaign) are the height of folly. To my mind they are both examples of eclipses of reason, in both cases the credibility of the green movement in my mind has been dragged through the mud by no one other than the Green movement themselves.

In the case of chlorine, I freely admit that there are some very horrible chemicals which have chlorine in them but on the other hand their are some substances with chlorine in which are benign and very important for our health. Greenpeace fell into one of the most basic traps documented in the book straight and crooked thinking, of confusing some with all. For an organisation who are claiming to be given out advice based on science and reason they should be deeply ashamed of that episode. The current antinuclear campaigns seem to be the product of the same type of bad thinking.

Another of the hard unit cells

Dear Reader,

After my success with the sodium nitrate I will now present tripotassium hexacyanoferrate(III) which is an example of a monoclinic cell. Again we have to start with drawing a box to make our cell. The lengths of the cell are 7.047, 10.400  and 8.384 Å. Two of the angles (alpha and gamma) are 90 degrees while the beta angle is 107.29 degrees.

This will give us a box which is more complex than an orthorhombic box.

We start by adding iron atoms, the fractional coordinates of the iron atoms are 0 0 0 and 0 0.5 0.5 which means we have two iron atoms in the unit cell.

We next have to add the potassiums at the following fraction coordinates 0.000 0.000 0.500, 0.000 0.500 0.000, 0.5025 0.7700 0.6252, 0.5025 0.7300 0.1252, 0.4975 0.2700 0.8748 and 0.4975 0.2300 0.3748.

We should now understand that we will have six potassium atoms to go with our two irons.

Next we add the cyanide carbons

These are at the following fractional coordinates

0,1875	0,9480	0,2102
0,1887	0,945	0,886
0,8795	0,8317	0,9712
0,8795	0,6683	0,4712
0,8113	0,445	0,614
0,8125	0,448	0,2898
0,8125	0,0520	0,7898
0,8113	0,0550	0,1140
0,1205	0,1683	0,0288
0,1205	0,3317	0,5288
0,1887	0,5550	0,3860
0,1875	0,5520	0,7102

We should understand that they are all fully inside the cell so we have 12 cyanide carbons.

Next we do the cyanide nitrogens

0,8004	0,7335	0,9515
0,2974	0,9120	0,8160
0,2962	0,9180	0,3361
0,8004	0,7665	0,4515
0,7026	0,4120	0,6840
0,7038	0,4180	0,1639
0,1996	0,2665	0,0485
0,7026	0,0880	0,1840
0,7038	0,0820	0,6639
0,1996	0,2335	0,5485
0,2974	0,5880	0,3160
0,2962	0,5820	0,8361

Now lets have a look at what we have done, from the side we can see how one of the angles (beta) is a long way from ninety degrees.

Side view of unit cell

Now we will have a look from a different angle.

The front view of the cell

Here are the x,y,z coordinates of the atoms on a conventional 90 degree and 90 degree set of x y and z axis. I have marked on bold the iron atoms which are at the corners of the cell.

46
XYZ file   for : K3Fe(CN)6
K	0.28089	-3.45899	-5.16955
K	-5.00083	0.38661	-3.78117
K	5.38365	0.38134	-3.21339
K	0.10193	4.22694	-1.82501
K	-2.32040	-2.87755	-1.40161
K	2.82526	-0.96562	-0.24795
K	-2.82526	0.96562	0.24795
K	2.32040	2.87755	1.40161
K	-0.10193	-4.22694	1.82501
K	-5.38365	-0.38134	3.21339
K	5.00083	-0.38661	3.78117
K	-0.28089	3.45899	5.16955
Fe	-4.91135	-3.45635	-5.45344
Fe	5.47313	-3.46163	-4.88566
Fe	0.19141	0.38398	-3.49728
Fe	-5.09031	4.22958	-2.10890
Fe	5.29417	4.22430	-1.54112
Fe	-5.29417	-4.22430	1.54112
Fe	5.09031	-4.22958	2.10890
Fe	-0.19141	-0.38398	3.49728
Fe	-5.47313	3.46163	4.88566
Fe	4.91136	3.45635	5.45344
C	4.80935	-2.73005	-3.21574
C	0.69724	-1.37587	-2.85930
C	-1.59727	0.07097	-2.84632
C	0.66992	1.11497	-1.76490
C	-3.38358	3.91480	-1.26682
C	4.72002	2.46500	-0.96219
C	-4.72002	-2.46500	0.96219
C	3.38358	-3.91480	1.26682
C	-0.66992	-1.11497	1.76490
C	1.59728	-0.07097	2.84632
C	-0.69724	1.37587	2.85930
C	-4.80935	2.73005	3.21574
N	0.98970	-2.42716	-2.50303
N	4.41252	-2.27534	-2.24005
N	-2.64379	-0.14067	-2.41469
N	-2.39058	3.70212	-0.72368
N	4.38940	1.41403	-0.63999
N	0.95847	1.56933	-0.75174
N	-4.38940	-1.41403	0.63999
N	2.39058	-3.70212	0.72368
N	-0.95846	-1.56933	0.75174
N	-4.41252	2.27534	2.24005
N	2.64379	0.14067	2.41469
N	-0.98969	2.42716	2.50303

If you want a free program (free to academic users only) then I would suggest ORTEP which I have provided a link for on the right hand side of this blog.

Should Assange have been censored ?

Dear Reader,

I am sure that you will be aware that offensive or other legally troublesome words can be censored using a bleep. For example if I go on the radio and say I think that “X is a stupid idiot”, then the radiostation can prevent me from making the offensive statement by bleeping the words out.

I would be interested to know if the UK police considered censoring Mr Assange’s speech by using a large fog horn or a similar device. The fog horn was suggested by my legal advisor, while I would go for a very loud rave party or a device from Japan.

I reason that if he chooses to run away from English society and the english legal system then we should consider if he should be free to make a public speech into England. A range of methods exist for jamming things like radio transmissions, as a person (G7LSZ / SA6BID) with years of experience of chasing weak (and not so weak) signals and trying to talk to people in far flung exotic places I know something about jamming.

The most easy system to jam is a conventional FM system, if you can put a unmodulated signal within half the IF pass bandwidth of the receiver at the aerial which is about ten times bigger than the wanted signal then you will make it impossible for the user of the receiver to tune into the wanted signal. This is because of the capture effect which is seen in the series of non linear stages used in a FM receiver.

There are anti-jamming countermeasures which can be taken against this type of jamming, the most common one is to use two aerials and an adjustable delay line and some electronics to cancel the jamming signal. I predict that the best counter-countermeasure for the jammer is to them either use two jammers or to use an aerial array plus some electronics (or maybe just an electromechanical relay) to change the direction from which the jamming signal comes from. I suspect that the Lorenz system which was used in early airport ILS systems could be adapted to give a very good jammer.

AM systems are harder to jam, this is because the signal path in the receiver is more linear, my most simple suggestion for radio jamming of conventional speech signals is to introduce a strong unmodulated signal about 1 kHz from the carrier of the original signal. This will have several effects on the receiver. It will reduce the gain of the receiver by acting on the automatic gain control (AGC) which is a vital part of an AM system, also it will generate a whistle noise when it beats with the carrier. An AM modulated jamming signal is properly better for several reasons.

1. People like me if we were strongly motivated to tune in to a AM broadcast which was being jammed with a simple carrier would be likely to turn off the household radio and start to use a communications grade radio such as a FT-450 or a FT-1000 which has a good notch filter which operates at an IF, or if you were using a cheaper communications grade radio you might flip from AM to SSB and then use which ever sideband which was cleaner.

2. The mixture of random babble which the soviet jammers used would have been more distracting to a person trying to tune into VoA than just a blank tone.

But the frequency hoping and spread spectrum things like GPS are very difficult to jam as these systems constantly change the carrier frequency in a pseudo random manner, unless you have real time access to the algorithm used to tell the transmitter and the receiver to follow each other then it is impossible for the jamming transmitter to follow the signal you are trying to jam. If you widen the jamming signal by changing from something like a signal modulated with an audio tone to something wide like fast scan TV then you tend to reduce the spectral power density. Unless your target is equally wide as your jamming signal then it is unlikely that you will be able have any jamming effect.

But there is a final option which I have inadvertently caused, I was once running 100 watts into a 19 element Yagi array (circa 4000 W ERP) at the G8EYC club at Imperial College, I was beaming south east towards France in the sincere hope of getting a VHF signal over the channel (I did not manage to work France that day, I did it much later running a much lower power as a PhD student from Beacon Hill near Loughborough using a 25 W ERP). I moved to the upper end of the 145 MHz band, and one person spoke to me and told me nicely that I was desensing his receiver. What I had done was to put a strong signal within a few MHz into his front end. This drove it into a non linear state where the RF stage was becoming saturated, as a result the gain for all signals was being reduced.

I think for audio jamming I always thought that the most effective way is to either use the AGC in the human ear to blot out the wanted signal, this in the case of Assange could be done using a fog horn or to exploit a nonlinear effect in the human ear. This has been done for years as a method of drowning out unwanted yelling by playing loud music.

But some people in Japan have come up with something even better, this is the audio version of motorboating. In radio equipment a self inflicted EMC problem is often known as motor boating as it commonly makes a sound like a motorboat engine running at low revs.

If the RF equipment is unstable when attached to a RF load such as a 47 ohm resistor then it is a defect such as a parasitic oscillation which has developed into a real demon oscillation. This fault suggests that a RF stage is unstable, the way to cure this can be to improve the input / output isolation and/or neutralise the stage. Or add some damping to the stage, my late friend Don always wanted to use passive grid circuits for 4X150 power VHF amps this has the advantage that it is very stable while I have always used active grid which is far less damped.

Motorboating only occurs when RF is emitted from a device which re-enters the system and then disturbs it, these effects tend to be worse as the power level increases. I have experienced once in my youth, I had a 27 MHz rig which has poor filtering on the power lead (someone had disconnected a decoupling capacitor). Here the RF which was entering the rig via the power lead was causing the rig to increase this own RF power output, this caused the RF output of the rig to rise until something happened which caused the RF output to drop catastrophically. This caused the RF power to drop greatly, and the increase would start again. It was not doing any harm to the radio it was just an annoyance, and I noticed that if the power was turned down that the effect occurred more slowly.

A five minute job with a soldering iron soon cured the problem, all I did was to reattach the ceramic capacitor.

This invention from Japan works by delivering a person’s voice back to their ears with a short delay, this disturbs the processes in the brain required for forming speech. So as this feedback loop uses a person’s own transmitter (voice) to cause a transmitter defect I think it should be considered as being a phenomena in the same class as motorboating. If I am right to consider it a form of motorboating then the louder a person trys to speak the stronger the effect will be, which will please anyone who is looking for the “smart bomb” of jamming for audio systems. In common with motorboating it does can work without causing any harm to the system which is troubled by it.

If you want to read about the Japanese invention then look here, here and here

I would like to know what my readers think of the idea of censoring Assange with a machine which robs him of the ability to talk while it is pointed at him.

Non cubic cells

Dear Reader,

When I was at my brother in law’s wedding I took the chance to bring to Sweden a book which I consider to be one of my “secret weapons” in chemistry. It is not the most advanced book in my collection but it is a fun book. It is a 1960s text book which is intended to be a bridge between A-level chemistry and university chemistry.

Now if any of you have a copy of “Chemistry: A Unified Approuch” by Buttle, Daniels and Beckett then I suggest that you turn to page 70 of the third edition. But the rest of you will have to keep on reading my blog.

I want to discuss with you some crystal systems and unit cells which are a little different to the rock salt cubic one which I have already considered.

Now if we make a start with a cube which has been stretched or squeezed in one direction we will have tetragonal. The example which the book gives is mercury(II) cyanide. Now this is a compound which I suspect will get some less mature people angry. The mercury part may outrage them while the cyanide part will also get them in a pickle.

Before we go any further I need to share something with you, sometimes when we learn about chemistry we need to learn about the chemistry of not so nice to handle substances. If I was to try to write a chemistry course which either only included “nice” harmless substances or only contained wild and scary compounds then I would have done the students a great wrong. To understand chemistry you will need to understand both nice innocent compounds and some real nasties. While I do not advocate giving the undergraduates things like plutonium, acrylamide, brucine and large amounts of KCN to do experiments with I still need to teach them about these things as they will need to have an understanding of these things for the good of society.

To fail to teach chemistry students about “horrible” chemicals is as stupid as not teaching law students about “what to do when people break the law”. While law students could be taught about all the laws which relate to nice people who make a point of obeying the law, they need to know about legal reasoning of criminal law, and the details of the laws which deal with bad people.

I have very little sympathy for the idea that I should not teach students about chemicals which they can not handle in their teaching lab. I also have precious little sympathy for people who use (or want to use) the more hazardous chemicals in a reckless manner, I am strongly in favour of responsible chemistry.

Now I am coming down from my soap box, and returning to the chemistry.

O. Reckeweg and A. Simon, Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische Chemie, 2002, 57, 895-900 is the most modern determination of mercury(II) cyanide. This compound is in a cube which has been squashed. The cell has two sides which are 9.6922 Å long and one which is 8.9015 Å long. The first two are the x and y axis while the last is the z axis. The z axis is blue while the other two are red and green.

We need to add the mercury atoms at the following locations

0,2500	0,7880	0,8750
0,2500	0,7120	0,3750
0,2120	0,2500	0,1250
0,2880	0,2500	0,6250
0,7500	0,2120	0,1250
0,7500	0,2880	0,6250
0,7880	0,7500	0,8750
0,7120	0,7500	0,3750

Here is what our cell will look like with the metal atoms

The mercury atoms in the cell

Next we should add the cyanide carbons at the following locations

0,0464	0,7950	0,8366
0,0464	0,7050	0,4134
0,4536	0,7950	0,9134
0,4536	0,7050	0,3366
0,7050	0,9536	0,5866
0,7050	0,5464	0,6634
0,7950	0,9536	0,1634
0,7950	0,5464	0,0866
0,9536	0,2050	0,1634
0,9536	0,2950	0,5866
0,5464	0,2050	0,0866
0,5464	0,2950	0,6634
0,2950	0,0464	0,4134
0,2950	0,4536	0,3366
0,2050	0,0464	0,8366
0,2050	0,4536	0,9134

Here is the cell with the carbons and the mercury atoms

The cell with the carbon and mercury atoms in it

Lastly we add the cyanide nitrogens, I know that this might be a lot for you to read but think of how I have to type all the the values !

0,2035	0,9280	0,1785
0,2965	0,9280	0,5715
0,2035	0,5720	0,0715
0,2965	0,5720	0,6785
0,5720	0,7035	0,3215
0,5720	0,7965	0,9285
0,9280	0,7035	0,4285
0,9280	0,7965	0,8215
0,7965	0,0720	0,8215
0,7035	0,0720	0,4285
0,7965	0,4280	0,9285
0,7035	0,4280	0,3215
0,4280	0,2965	0,6785
0,4280	0,2035	0,0715
0,0720	0,2965	0,5715
0,0720	0,2035	0,1785

Now we have all the atoms in the cell, here it is in all its glory.

Here is the cell with all the atoms in it

Now we have the whole of the cell, the interesting question is what is the coordination number of the mercury. Now at first look it might appear that the coordination number of the mercury is four. But it is only two. If we look at the coordination environment of a mercury we will see that we only have two cyanide carbons in the right places.

The coordination environment of a mercury atom

Lead(II) iodide has a series of different hexagonal crystal forms, but the most simple one is described by B. Palosz, W. Steurer and H. Schulz, Journal of Physics: Condensed Matter, 1990, 2, 5285-5295.

After the endurance test of typing the values for the mercury cyanide this one should be quite a nice rest.

The cell is a hexagonal cell, the a and b edges are 4.558 Å long (these are the x and y axis {red and green}) while the z axis is blue and the c edge is 6.986 Å long.

We have a lead atom at each vertex of the cell, so the fractional coordinates of the lead is 0 0 0 (well that was easy).

The first iodine is at 0.3333, 0.6667, 0.2675 while the other is at 0.6667, 0.3333, 0.7325.

Here is what the cell looks like.

Lead(II) iodide cell

Potassium chromate, well I do not know why the book seems to choose toxic examples so much but this is a good example of an orthorhombic cell.

We start with a box which is 7.662 Å by 5.919 Å by 10.391 Å.

Then we add the potassium atoms at the following fractional coordinates

0.1656, 0.2500, 0.0857

0.5100, 0.7500, 0.1998

0.6656, 0.2500, 0.4143

0.0100, 0.7500, 0.3002

0.990, 0.2500, 0.6998

0.3344, 0.7500, 0.5857

0.4900, 0.2500, 0.8002

0.8344, 0.7500, 0.9143

As all of these potassium atoms are totally inside the cell, we have eight potassium atoms in our cell.

Next we need to start to add the chromium atoms these are at

0.7291, 0.2500, 0.0794

0.2291, 0.2500, 0.4206

0.7709, 0.7500, 0.5794

0.2709, 0.7500, 0.9206

As all the chromiums are fully inside the cell we have four chromiums in the unit cell which means that the potassium to chromium ratio is 2:1. This is in agreement with the formula which we are expecting for the solid.

Lastly we add the oxygen atoms to the cell.

We have four groups of four oxygens which are at

0,1982	0,7500	0,0704
0,1971	0,5225	0,8471
0,4846	0,7500	0,9200
0,1971	0,9775	0,8471
0,6971	0,9775	0,6529
0,9846	0,7500	0,5800
0,6982	0,7500	0,4296
0,6971	0,5225	0,6529
0,8018	0,2500	0,9296
0,8029	0,4775	0,1529
0,5154	0,2500	0,0800
0,8029	0,0225	0,1529
0,3029	0,0225	0,3471
0,0154	0,2500	0,4200
0,3018	0,2500	0,5704
0,3029	0,4775	0,3471

I hope by now that the penny will have dropped the cell has a magic point at 0.5, 0.5, 0.5, this is a centre of symmetry. If an atom appears at fractional coordinates q, w, e then another atom will appear at 1-q, 1-w, 1-e.

If we add the oxygens to the cell we will get a tetrahedral arrangement around the chromium atoms, for two of the chromium atoms we have to borrow an oxygen from another unit cell. This finishes off the potassium chromate cell. It also helps explain why chromate is so toxic, the chromate anion is so similar to a sulfate anion that it can pass through cell and nuclear membranes in the same way as a sulfate anion can. The chromate which enters the nucleoplasm can get reduced to chromium(III) which can then form very long lived complexes with the DNA in the cell.

The other crystal systems which have angles which are not right angles are much more of a pain to draw so we will not do them today.

I will put up the pictures of the potassium chromate later.

Electrostatics and chemistry

Dear Reader,

Well it is time to start to educate the first years again, we are going to start with some of the chemical bonding in solids and liquids. Before you ask in the gas phase a typical molecule is all on its own. Normally a molecule in the gas phase spends most of its time not in contact with any other atoms, surfaces or molecules.

In the condensed (liquid and solid) phases many species form weak bonds to other species which do not involve full covalent bonds.

The most obvious one is ionic bonding, the reason why a salt such as sodium chloride (common salt) is a solid is the electrostatic effects which cause the sodium ions to attract the chloride ions. Maybe we should consider for a moment the wonders of ionic bonding.

Before we start the sensual journey into chemistry I think it is important that I share something with you. The basis of almost all chemistry is electrostatics, this explains ionic and covalent bonding together with the way that atoms and molecules interact with each other without forming full strength bonds.

Now for a moment I will digress off into electronic engineering, in high speed high gain valved electronics it is common to use a tetrode valve. The reason is that the capacitance between the anode and the grid tends to add a positive feedback loop into many circuits. In general positive feedback is very bad in amplifiers as it tends to lead to instability.

The best way to deal with this problem is to change from a triode to a tetrode. The tetrode has a cathode, an anode, the control grid and a second grid between the control grid and the anode. This extra grid is known as a screen grid. In DC terms it is normally at a voltage slightly lower than the anode and in RF terms it is connected to ground.

What this screen grid does is to act as electrostatic screen which reduces the influence of the anode on the control grid. As a result the valve has a lower capacitance between the anode and the first (control) grid. Because of this the valve is far more easy to use in high speed high gain circuits.

The high power triode valve (3CX2500) has a grid anode capacitance of 20 pF while tetrode valve with a similar power level (4CX3000) has a control grid to plate which is about 100 times smaller. For those of you who want to understand what the valve numbers mean, the first number is the number of electrodes, the C means ceramic (instead of glass), the X means an external anode and the number is the power which the anode can dissipate.

In a similar way the inner clouds of electrons in an atom tend to partly screen out the electrostatic effect of the positively charged nucleus. As an example we should consider a point charge which consists of nine protons together with some neutrons to hold them together.

If we make a graph of the electric potential against distance from the point charge then we will see that the closer we get to the point charge the higher the electric potential is, this is the upper blue line. If we add the effect of putting the positive charge in the centre of a cube (50 pm) which has an electron at each vertex. Then the effect of the positive charge is much weaker outside the atom.

 

Electric potential as a function of distance from the centre of the atom, with and without the effects of the electrons.

 

Feel sorry for Tony Farmer ? Don’t !

Dear Reader,

It has come to my attention that a young man broke up with his girlfriend, it is a rather sad thing which sadly happens every now and then. But rather than taking it like a man he choose to beat the living daylights out of the young lady. A film of what he did can be seen here.

I think that the judge gave him quite a light sentence of only three years, I also hold the view that Tony Farmer is a thug who made a choice to commit a violent crime.

I find it interesting and disturbing that at least one sports writer seems to write up the event as if it is a shame for Tony Farmer that he is going to jail. I think it is high time that we stop allowing sports stars to ignore the same moral and legal norms as those which apply to the rest of the population.

Maybe as these sports stars are role models for many people the jail sentances should be made longer to make an example of them.

I would be interested to know if Mr Farmer will be allowed to finish high school in prison and then apply to play basket ball at university again.

Honesty about the things we dislike

Dear Reader,

When I recently saw the comments of Yehuda Bauer about one of the most horrible tales (large scale production of soap from human fat) from the 20th century, this gave me reason to think. He wrote

“The reason why one has to be accurate is that one has to exercise tremendous responsibility and deep respect towards the victims and their relatives and towards the memory of the millions of Jewish dead. What the Nazis did is horrendous enough; we do not need to believe the additional horrors they thought about but did not have time to realize. The Holocaust deniers waiting in the wings are eager to pick up any inaccuracies we may inadvertently commit, and we should not ease their “work.” “

The key take home message is that there are some very horrible things which have occurred, but to make up (or repeat) lies about these events to make them even worse is wrong. These lies are evil (I do not use the E word lightly) as they distract us from the truth and then these lies make it more easy for those who wish to deny that the truth occurred to do their vile “work”.

Also such lies are deeply disrespectful to those decent people who were involved in these events.

I have seen a disturbing trend for people to be very reckless with the truth when considering threats to health and the environment. I hold the view that we need robust environmental rules which are based on honest reason and science rather than on hype, hysteria and on the ability of a group to shout louder than others. In the same way as industry should not be able to dictate the law, the environmental pressure groups should not be allowed to dictate the law.

I am sure that my readers would be unhappy with the following arrangements

1. BP and Shell being put in charge of setting and enforcing oil field health, safety and environmental rules.

2. AECL (Atomic Energy of Canada Limited) and BNFL being allowed to choose the nuclear safety laws

3. Ford motors and Volvo being allowed dictate all the laws which relate to the use and ownership of cars, trucks and buses.

In the same way we should not allow the environmental pressure groups to dictate the law, I think that we need laws to be made in a more fair way. I think that one of the best swords in our armoury against the worst nonsense which is based on either industrial self interest or the self interest of the pressure groups is to ask them to provide details of the logic and data which are behind their claims.

I have noticed a worrying behaviour in some activists, when questioned about their views and the things which they claim they get angry and make comments “I am telling it as it is” or they play the card “that unless you have experienced it first hand, then you are not entitled to have an valid opinion” or try a series of other tricks.