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Friday, February 14, 2020

Covid-19 and Racism

This blog was triggered by some ning nong here in New Zealand shouting at a woman of Asian decent to go back home.  It happens that she is a MD and has never been to China and is a New Zealand citizen.  That sort of attitude is highly unacceptable in New Zealand but there are always some outliers.

But let's face it, we all are racists, or religousists or Politicalists or some other "ist".  It is the way we evolved.  One group, insiders of their own group, fighting another group and in earlier times, killing all the men and taking the woman for their own tribe (and sometimes eating the men).  Perhaps we should call them all Clanish.  Whatever clan you belong to, you believe that the other clans are of lesser status and of lesser value.  We have minor religious variations leading to clanishness (Ireland), Political differences (The US of A), color (nearly everywhere) and on and on it goes.

The Chinese themselves are no exception.  They are arguably the most clannish of people.  When they immigrate to another country, they tend to form enclaves that we call China Towns such as in San Fransisco and Vancouver and certainly do not want their young people marrying outside their clan.  As such, they might show a little understanding when the surrounding population is a bit clannish too.

This blog, though is mainly concerned with whether or not we have something to fear from China with regard to diseases such as the latest Covid-19.  What are the facts.

Many of the viruses that most threaten us are recent zoonosis; recent transfers from animals to humans.  The ones that have been in the human population for a long time are less deadly since the population has developed some partial immunity to them and the virusis have modified (evolved) their genetics* so that they spread more easily.  This involves not killing their host rapidly or they burn themselves out.  The body takes a week or so to develop immunity to a given virus so if it is slow acting, the body may take care of it if you can keep the person alive for that length of time.  This is not to say that old familiar viruses do not kill people.  They do.  It is just that the new ones, recently transferred from animals tend to be more deadly.

* That is actually a bad way of expressing it.  In fact, varieties of the virus which kill their host rapidly, die out while ones that only make them sick spread far further and wider.  Ones that show no symptoms for some time while being able to jump from human to human spread the most.

So is China a threat.  Well yes it is for a number of reasons.

First there are very large populations of Chinese living in close proximity  in China so a virus, once caught by one person can spread rather rapidly.  A pretty good population of infected people can be established before it comes to the attention of the officials.

A second problem was illustrated by this latest Covid-19 virus.  The doctor that reported it was chastised by the local government for spreading false news.  There is a fairly large and established level of corruption and fear of loosing status in China.

Then there is the problem of the huge number of pigs and chickens in China in close proximity.  Some viruses spread between animals before jumping to humans and having animals in huge numbers in close proximity to each other and to humans can encourage such outbreaks.

Add to this the great variety of animals that the Chinese use for food.  There are markets for wild food including snakes, bats, cats, dogs and essentially anything made of meat.  In addition many exotic animal parts are used in Chinese medicine.  All this brings humans into close proximity with a whole host of viruses.  It is amazing that we don't have more outbreaks.

It is notable that when a new virus appears in a human population, it takes around 6 months to develop a vaccine for it.  In the mean time we have to fall back on old methods of quarantine and to give credit where credit is due, the Chinese government has been magnificent in this regard.  Due to her stringent methods very few cases of this disease have been seen outside of China.

So yes, it is likely that more of these viruses will come from China than from other countries but as long as the Chinese apply quarantine measures as they have been doing, we are in pretty good shape.  Let's hope other countries can take a lesson from the actions of the Chinese. Not all new viruses have come from China.

However, there is no justification for being racist against Chinese people because of the situation in China.

Monday, January 20, 2020

Clearing Australian air pollution

There is not much you can do to clear the outside air in Australia from all the pollution caused by bush fires short of taking climate change seriously but it is a different story inside your house.  The problem is all the tiny particles of soot, dust and other aerosols created by the fires.  There are P10's, P5's and even P2.5's.  These tiny particles are sucked deep into the lungs where they cause all sorts of problems.

The technology to clear the air in your house is the same that is used to clear particulates from smoke stacks.  Look at the smoke stacks in any modern country and at the most, they put out water vapor clouds that rapidly dissipate in the air.  It is called electrostatic precipitation.  Home units are sometimes called negative ion generators.  So how do they work.

The 220 volt AC is fed into a transformer that steps up the voltage.  (does anyone know what voltage they use.  Haven't been able to find the info).  The high voltage is then run through a rectifier such as a wheatstone bridge to give pulsating high voltage DC power.  If there is need to smooth out the power, a capacitor can be connected between the positive and negative outputs of the Wheatstone bridge.  The negative side is then run through a seriously strong resistor so that you can't get a shock (at least not a bad one) if you touch the spike.  the spike is where the electrons come off into the air and for reasons I won't go into, a spike is the best configuration to send electrons into the air.

The electrons stick to particles in the air, charging them and as the charged particles come close to surfaces, they are attracted and stick.

The positive side can  be grounded to your power supply ground but better still, put the grounding wire provided with the metal end into a large shallow body of water with a pinch of salt in the water.

One of our sons had breathing problems when he was younger so we put one of these on a small shelf above his bed.  It wasn't long before the wall behind the bed turned black from all the charged particles that the electrostatic charge glued there.  With a grounded body of conductive water, you will see the water get grungy as charge particles are attracted to the water.  If this doesn't happen, you either have very clean air (unlikely) or you have an inferior  brand of negative ion generator.

Wednesday, December 4, 2019

Clearing mines

Clearing mines and other ordinance left on the world's fields of battle is dangerous and expensive and is taking far too long for the farmers who want to get back on their land and farm in safety. Doing it by hand as is done at present is so slow that it will never be finished. I don't know if it is true but I have read that some first world war battle fields are still being cleared. All the un-exploded ordinance and especially the mines are exerting a huge toll in life and limb among the innocent citizens of the area who didn't want the war in the first place. Why can't we mechanize mine clearing.

Start with a main battle tank such as the British Centurion, Israeli Merhava or Soviet T series tank. Strip it of the turret and gun and every bit of equipment that was necessary for battle. With the reduced weight we now have lots of spare power available. Weld on a cupola where the turret was located that can withstand the shrapnel from an exploding tank mine and equip it with the standard prism system so that the driver can drive in safety from within the tank.
 Image result for image british centurion tank

Connect a realy grunty hydraulic motor to the main engine. Now we are ready to start.

Build a cylinder with teeth/scoops which is a little longer than the width of the tank and suspend it on arms coming from the sides of the tank. The arms raise and lower the cylinder hydraulically to control the depth of cut. This is a little like the huge equipment that harvests coal but is a cylinder, not a wheel.
 Image result for surface Coal mining equipment image

 The cylinder is situated in front of the tank and rotates with the forward side moving upwards. A hydraulic motor rotates the cylinder at, say, about 60 revolutions per minute. The cylinder is robust enough to take the explosion of a tank mine. Remember, the mine is no longer tamped and its force can blow upwards and outwards. The cylinder scoops up the top, say, 50cm of soil and pushes it backwards over the top of the cylinder, dropping it into a vibrating grid made of really grunty steel bars. The mesh size is such that it catches tank mines. anti-personell mines and cluster munition. The grid has an orbital vibration so that anything caught is bounced off to one side and dropped in a windrow beside the tank. Anything surviving this rough treatment is exploded by a sapper.

Below this grid is a second grid of finer mesh that catches anything down to a M16 bullet. This material is also conveyed to the same side of the tank and sieved out material is dropped in the same windrow. The soil drops between the cylinder and the  front of the tank.

Any valuables including brass go to the owners of the fields. They deserve some recompense for what they have suffered.

The driving compartment is air conditioned. Most of the battle areas of the world are tropical and the driver must be comfortable to be able to operated for many hours a day. Make the driving space like a modern agricultural tractor.  Remember, with all the extraneous weight removed, we have lots of spare power.

While we are at it, lets analyze the soil and if it needs something like lime or some nutrient to make it fertile lets add it to the discharging soil. Attach a couple of hoppers to the back of the tank and a metering system to add whatever is necessary to the soil. Once again, the farmers deserve something extra for their long suffering.

 Image result for image fertilizer spreading equipment

A grader attached to the mine clearing crew finishes off the cleared field.

 Image result for image graders operating

All finished areas are, of course, entered in a GIS map using GPS technology so in years to come, it is clear which areas have been cleared. Start with the most arable land so that the farmers can get on with their lives.

Surely the engineers that came up with battle tanks with all their sophistication could come up with a machine to clear mines rapidly and effectively. How great would it be if one of the engines of destruction, the main battle tank, did some good instead of harm.

Saturday, October 26, 2019

Touch Screens in cars

Touch Screens in cars are a really, really bad idea.  Look at all the kerfuffle world wide about using a cell phone in a car.  At least with a cell phone, you're likely to be holding it up by the steering wheel as you dial or touch the green icon to answer the phone.  Or, shudder, you type in some destination into the navigator.  Some part of your vision still records what is going on on the road.  With a touch screen you have to take your eyes right off the road to operate them and it is not a one touch operation.  You have to do multiple touches to get to the application you want to use.
 Image result for image touch screen in car

Remember those old car radios.  There was a nob on one side to turn it on and off and to increase or decrease the volume.  There was another nob on the other side to tune in the stations.  Then between the two nobs were five or six pull-out, push-in buttons.  You pulled one out, tuned the radio and then pushed it back in again.  From then on if you wanted that station you just pushed that button.  Ditto with the rest of the pull-out buttons.  You had five or six different stations all at your finger tips, all without taking your eyes off the road.
 Image result for image old car radios

Or come forward a little to a more modern radio.  Up at one corner is a toggle switch which you can feel.  Once more no need to take your eyes off the road.  Push it quickly and the radio tunes up or down  depending on which side of the button you pushed.  Hold it down for 2 seconds until you hear a beep and it will run up or down the radio spectrum until it finds the next channel.  On the other side is a second tactile toggle button.  Push one side and the volume goes up, the other side and the volume goes down.  In all of this no need to take your eyes off the road.

A more luxurious system has all the tactile buttons on the steering wheel.

If we are all up tight about cell phones, how much more dangerous are touch screens.

And don't get me started on autonomous cars.  Besides the fact that I really like driving, they seem to me to be a bad idea.

Have you ever heard of a soft-ware program that couldn't be hacked.  Recently we have had the UK health system computers hacked and bank after bank.  If anyone should have state of the art protection surly it is these institutions.  Just imagine what happens when some warped 14 year old genius in his mom's basement manages to hack into the system and shut down one of the functions.  Whole cities come to a stand still.  And this could happen even if only a small percent of the cars are autonomous.

Worse still, have you being paying attention to the revelations of Snowdon and Manning.  The secret services have little or no inhibitions against causing collateral damage (killing innocent bystanders) and being human they also make mistakes.  Imagine they have decided that a certain car is carrying a terrorist they want to eliminate.  They send the car into a tree or over a cliff at high speed.  Or they targeted your car by mistake or perhaps they send the car into oncoming traffic and you just happen to be on the other side of the road.

In addition, with your car continually connected to the internet of things (G5), they always know where you are and what you are doing.  And don't give me that old saw that if you are not doing anything wrong you have no problems.  That is such a  discredited a argument that it doesn't deserve another paragraph. This really is a Big Brother scenario.

Have you ever heard of a computer program that didn't need patches and upgrades to fix glitches that the programmers didn't anticipate.  In the first death in a self driving car, the computer didn't recognize a truck coming from the side and thought it was a road sign.  We don't need programmers experimenting with our lives as we travel down the road at highway speeds.

What do I want in a car.  I want all the great engineering that is coming out in Electric cars but none of the bells and whistles.  And I want the lower price that comes with this.  I want any controls to be tactile, not touch screen.  And I want the pleasure of driving my own car.  This isn't for everyone but I bet there is a huge market out there for such a car. If I need navigation, I'll velcro my phone on to the dash board.

If you want to wow me, make all surfaces of the car generate electricity when they are in the sun.  No, I don't expect to be able to drive just on the power the skin of my car generates but it will be a nice little bonus and might get me home. when  I have forgotten to charge up when I should have.  Some years ago a home made electric car visited us here in New Zealand.  He pulled a trailer and the top of the trailer was covered with solar panels.  He said he could carry on driving at 20k/hr if it was a sunny day but his batteries were flat.

Wednesday, October 2, 2019

A new Battery technology

What would you say to a battery for static use that could be completely charged and discharged with no degradation of it's capacity over time.  A battery that today will hold ten kWh and in one year it will still have the same capacity. A battery that has no self discharge and so if you charge it up and come back in a year it will still have the same charge. Better still, a battery that uses very common cheap materials in it's chemistry so should be pretty cost-effective when production ramps up. And none of it's materials (like Cobalt) are produced in countries that use child labor.

This is the hype around a new battery chemistry and they are already in production.

Now just a disclaimer here.  I am basing this article on the literature around this battery and have no experience myself in owning such a battery.  In fact, they are in the stage of ramping up production and I haven't been able to find what they cost at present or what they project the price will be in the future.

This is a flow battery meaning that a fluid is pumped through the battery that does 'the  necessary'.  It is a plating battery that plates Zinc onto 'shelves' of plastic (dosed with carbon, I believe, for conductivity) during the charging phase.  The Zinc is stripped from the plates back into solution during discharge.  The other ion is Bromine so this is a Zinc bromide battery.

It has been developed in Australia and production at present is quite small, measured in hundreds per week  but, clearly, if it's promise is fulfilled, production is bound to climb as revenue flows in from initial sales.

The cycle efficiency of this battery is said to be 75-80%.  If you put in a kWh* you will get an effective 0.75kWh back out.

* A kilowatt hour - in other words, a kWh could provide one kW for one hour (or half a kW for two hours etc.)

A disadvantage (minor) is that the plates must be stripped every three days to stop the build up of spicules of Zinc that would damage adjacent plates. In other words it must be totally discharged.  Apparently this is automated so it happens without your intervention.  I'm not sure what happens to the electricity which will be produced during a full discharge cycle but I can imagine it will be fed into the grid with the amount you earn from this being determined by the policy of your power company.

If you have more than one of these 10kWh batteries, power resulting from the stripping cycle could be fed into the other half of your batteries.  While operating,,,, one battery (or bunch of batteries) would be in use (discharging) while the other half would be charging.

Incidentally, some recent information on the mega Lithium ion battery provided to Australia by Tesla has shown some interesting results.  This battery holds 100mWh* of power and cost $66m.  It's first anniversary will be in November and based on the present rate of return, it will have returned $20m by that time.  A 30% pa rate of return.  Wow!!!  It is installed in a large wind farm so presumably the earnings are due to not having to waste wind-generated power when the grid is producing all it needs.  The power is then sent to the grid when the demand and hence the price is high.

* megawatt hour - one mW equals 1000kW

They could also be earning by buying power to charge the battery when power from the grid is in excess and hence cheap, and selling it back when there is a demand.

Another interesting wrinkle is that the response time of the battery is so fast when demand increases or decreases, unlike other sources of electricity, that the quality of the power is increased.  In other words the voltage and frequency are stabilized, unlike when other generation sources  with slower response times are cut in and out of the grid.

Presumable this quality improvement would be the same with any battery system including the ZnBr battery.

Of course, Li ion batteries degrade over time and this is partially compensated for by battery management systems that don't ever charge up the battery to it's full capacity or discharge it to zero.  This slows but does not stop the decrease in it's capacity over time.  Of course it means that the effective capacity of a Li battery is less than it's rated capacity.  Note that Tesla, in an emergency, can send a signal to her cars, allowing the owners to use the full capacity of the battery (at the expense of the longevity of the battery).

This points up the great advantage of the ZnBr technology over the Li technology.  The cost over time is bound to be less, and even more so when the price of the Zn battery per kWh becomes less than the cost of the Li battery as it is bound to do because of it's less expensive materials.  Note that this technology is only for static applications.  The Li ion battery is still king for mobile applications.

ps.  There is a Zinc bromide gel battery in the works.  No idea what it's characteristics are.