5G is Here

I downloaded a full-length feature film in one-and-a-half seconds, just the way the Captains of Telecom Industry had been promising. And it came in all of its 8K glory with Dolby Atmos sound and subscripts in fifty languages. Subscripts in fifty languages! That was a bonus - something the Tech Masters forgot to mention.

So I pushed my luck further - tried to download a few more 8K full-length movies. My cellphone storage soon overflowed, its motherboard melted and drained out of the dynamic island that had a thoughtfully placed hole just for this purpose. Oops, that was the 200MP camera. I then decided to upgrade my kit. Got a new 5G xPhone Pro Max Doubleplus with a full TeraByte of storage and pushed my luck even further - downloaded 60 full length 8K movies in 90 seconds (1.5 seconds each, remember?) with VR interactive interface, where you can tell Ranbir Kapoor to let go of the trident and go wear diapers. The phone storage overflowed again. The phone didn’t melt, but was hot enough to fry an egg on. So hot that I dropped it and its VICTA glass screen shattered into nano-diamonds that I sent to carborundum guys to make grinding wheels with.

Yet my exploration of the ultrafast, superhigh-bandwidth, imperceptibly low-latency technology was only scratching the surface. So I decided to upgrade my man pad further. I got four thousand hard disc drives of 6TB each from Nehru Place. I got a massive discount with which I will buy a new tortoise shell comb sometime later. Then I got some ten thousand kilometers of special low-loss cables to connect all these HDDs to a central switch. GISCO helped me steal the special switch from their only installation at the All-Visible-Universe Weather Forecasting Superstation. Poor fellas, they are back to measuring PM2.5 in Okhla again.

I then got down to downloading all the movies available on Earth and on Trisolaris, and downloaded fifty seven thousand six hundred full length 8K movies in eighty six thousand four hundred seconds of the day. All the birds nearby fell down from the sky upon the spinning of four thousand magnetic discs that disoriented their navigation. Next time I will buy only SSDs, I promise.

Now, I have about one lakh fifteen thousand two hundred hours of movies at my disposal - just about thirteen years of continuous viewing, no meal and toilet breaks. Popcorn is on me. Please come over.

                                                 —ooo—

2+2 Always Equals 4

In my school WhatsApp group, just like yours, there are old friends of all hues, moods, and temperaments. During one of the idle discussions a friend got peeved at another one’s logical arguments and said, “You engineers know nothing. Two plus two is not always equal to four!” The friend, who had taken offence, is a PhD in liberal arts and can’t be taken lightly. But the other guy too is an IITian and couldn’t be dismissed either.

Now, liberal arts scholars, whether from social science, political science or international relations tend to look down upon engineers. No doubt liberal arts is an important educational and intellectual input to the society. It provides a solid ground for studying social behaviour, diagnosis of discords, resolving international turmoils, and tells us how to eliminate suffering that we see all around. Engineers (and Scientists, and mathematicians, and Doctors) provide the tools to achieve what the liberal arts prescribe. They provide the machines, means of production, enhanced agriculture, cure the sick and bring about a general improvement in quality of life. Engineers and Scientists, unfortunately, also create means and weapons of destruction, which the liberal arts scholars attempt to keep sheathed.

But, my objection to the two-plus-two argument, which is often flaunted by the social scientist to quieten the argumentative engineer, is a fundamental one. Why use the language of the engineer, viz. mathematics to beat him? The engineer, or the scientist doesn’t get that argument at all. For him two plus two always equals four. The debate then goes into a spin and ends up with the engineer frustrated and the social scientist flustered.

Let’s get it right once again - two plus two always equals four. So, by negating the kindergarten arithmetic no argument can be won. If a social scientist does lean on algebra to buttress his complex social debate, let him come up with his own equations with social variables, such as:

rich + rich = super rich

(rich + poor)/2 = middle class

intelligent+stupid = mediocre

fascism + suffrage = benign dictatorship

We engineers will understand them perfectly. 

Oxygen Generarors and Concentrators

It is heartening and greatly reassuring to see that thousands of oxygen concentrators and generators are being brought in from all over the world. This is, indeed, a life saving step and is rolling out faster than expected. But, there is an urgent need to plan for their upkeep and maintenance.

These devices are from diverse sources and are manufactured by different companies. They are electro-mechanical devices with pumps, compressors, valves, heaters and motors, which require attention and repairs. There would also be seals and gaskets, pipes and joints, all of which are prone to aging, deterioration and/or damage. With continuous working it is inevitable that these oxygen machines will require maintenance, upkeep, spare-parts and service sooner than later.

Hospitals, which have installed large oxygen generators and hooked them to their oxygen pipelines need to be extra alert. A malfunction or sub-optimal functioning may endanger lives even before it is detected, let alone repaired.

What should be done to avoid disruption in oxygen supplies? 

1. Find out the brand, manufacturer and model number of your equipment.

2. Check if there are service technicians available for such a device in your city or neighbourhood.

3. Every major hospital should have an engineer. Find out if such an engineer has familiarised himself with the equipment.

4. Find out the list of operational and maintenance spares and order them without delay - airlift them.

5. Insist on a single brand for your establishment. Train in-house personnel in operations and routine upkeep.

Again, remember such devices are only a stopgap arrangement for a hospital. Any hospital, worth its name, should quickly install liquid oxygen storage and necessary distribution system. It is much simpler and can often be serviced by in-house personnel with minimal training.

THE OXYGEN CONUNDRUM

Oxygen is available in plenty in the atmosphere. It doesn’t have to be extracted from deep mines or manufactured in factories. It simply has to be pulled out of thin air, literally and figuratively, either by liquefaction or concentration. Then why is there such a serious and seemingly insurmountable shortage of this lifesaving gas in our hospitals? The COVID crisis has exposed the ugly underbelly of our hospitals, both government and private. The government, as usual, has become the target of all curses and insults by the media and ignorant public, which finds it easy to criticise the government for after that all other responsibilities are shrugged and forgotten.

Even large hospitals are seen to be using banks of steel cylinders, heavy and unwieldy, which are connected to the hospitals’ oxygen manifold and serve individual patients. There is no reason they shouldn’t have installed liquid oxygen storage facilities given their massive requirements. Smaller hospitals place the cylinder at the bedside of the patient that need to be replaced every few hours. Typical steel cylinders for medical use in India come in two sizes – 10 litre and 40 litre. They are made from seamless tubes of expensive CrMo alloy steel since the gas in them is stored at 150 bars or higher pressure. These 10 litre and 40 litre cylinders may weigh up to 18 and 40kg and accommodate only 1500 and 6000 litres of free oxygen respectively. So, an 18 kg cylinder delivers only about 2kg oxygen and the larger one contains about 8kg. Besides, as the pressure in the cylinder drops the rate of delivery drops as well.

Now, imagine the logistic nightmare our medical oxygen supplies are burdened with - expensive steel cylinders which need to be manufactured at great cost and the volumetric and weight inefficiencies of the delivery system. A 20kg cylinder gives only 2kg oxygen and a 50kg cylinder gives just about 8kg after which they have to be sent back for refills. Liquid oxygen, on the other hand, converts to over 750 litres of usable free gas for each kg of liquid. Let’s compare the logistics:

Delivery System	Total Weight including Oxygen	Deliverable Oxygen	Weight Efficiency of Supply Chain
40 litre cylinder	40+8 = 48 kg	8 kg	125 lt/kg
10 litre cylinder	18+2 = 20 kg	2 kg	75 lt/kg
Liquid Oxygen	1 kg pure oxygen plus a proportionate weight of the cold supply chain.	750 lt	500-750 lt /kg

                 There is a small weight penalty for liquid oxygen too since it is delivered by cryogenic lorries.

I am not even mentioning the cost of expensive cylinders, which is actually an unnecessary burden on the national economy. Besides, cylinders have to be handled, when empty and carried back to refillers. With liquid supplies there will be no handling of heavy cylinders by hospital staff, who could be utilized elsewhere more fruitfully. Besides, industrial cylinders repurposed for medical supplies, as is being done now, should ideally be flushed and purged of impurities to match the “drug standards” of medical oxygen.

Considering that almost all oxygen, industrial or medical, is obtained cryogenically by liquifying atmospheric air to below minus 183 deg C and then regasified to fill the steel cylinders, it is easy to skip the bottling activity and deliver liquid oxygen directly to hospitals to be gasified on the spot. Indeed most metal industries and factories, which use oxygen, have an onsite storage of liquid oxygen. There is no reason all large hospitals, which have been in business for decades, shouldn’t have such a storage. Indeed, it is a criminal neglect. Liquid oxygen is delivered by road lorries in a cryogenic supply chain from the oxygen liquefaction plants to the end users. Modern cryogenic storage tanks have such efficient insulation that they are often built in the open facing direct sun, yet lose very little oxygen from the tanks. Liquid oxygen, as supplied to hospitals, will also be inherently more pure for the simple reason that impurities have different temperatures at which they become liquid. 

There are two ways in which liquid Oxygen can be introduced in hospitals:

1. Large hospitals should install multiple cryogenic ground tanks of capacities ranging from 20 to 40 tonnes. They will be refilled by liquid oxygen lorries periodically. This is also the way most industries procure and store oxygen. 

2. There is a need to design smaller cryogenic tanks, not unlike large thermos flasks,  that can be delivered prefilled with liquid oxygen from oxygen plants to smaller hospitals just the way we get Liquefied Petroleum Gas in our homes. These tanks will be swapped with empty ones and each hospital can even have a few spare prefilled tanks for handling contingencies, temporary shortages, or surge in demands. This can also be an interim arrangement for large hospitals till their larger tanks are built.

Most hospitals are already pipelined for handling such supplies. Cryogenic tanks can, in most cases, be accommodated in the same or less space that banks of oxygen cylinders take up today. Liquid oxygen is stored at much lower pressures than compressed gaseous oxygen and is actually safer in handling and storage.

There will be a need to build a fleet of cryogenic tanker lorries exclusively catering to medical needs since purity levels of medical oxygen are more stringent than industrial oxygen. In fact medical oxygen is legally a drug and must meet those requitements. 

An adult breathes in about 10,000 - 11,000 litres of air (20% Oxygen) in 24 hours. He will breathe the same volume of oxygen (99%) in that period. Forty and ten litre cylinders will last only 13-14 hours and 3-4 hours respectively. Hence there is a need to create an uninterrupted supply of oxygen, which can be ensured only with liquid storage.

A ten-tonne lorry that carries, say 200 large cylinders, delivers only 1600 kg of oxygen. A ten-tonne cryogenic lorry, on the other hand delivers six times as much. The liquid supply chain removes eighty lorries for every hundred from our roads as well.

To summarize, there is an immediate need to promote, rather mandate, storage of liquid oxygen in our hospitals forthwith. There is no shortage of oxygen even today. It is the cumbersome supply chain that has let us down. The solution is easy and is staring in our faces.

Let's do it.

 

Lessons from the Texas Blackout of Feb 2021

The unprecedented, though not unforeseen, blackout in Texas has a lesson for energy planners in general and mechanical and electrical engineers in particular.

Texas is a relatively warm state of the USA. But, an unusual snow storm and resultant low temperatures caused the electricity demand to rise beyond previously known peaks. Unlike colder states, where building heating systems are gas based, Texans use electricity since the heating demand is low and sporadic. A grid collapse can happen even with a 5% overload. In practice the grid managers go for a cyclic or rolling blackouts - area wise or time wise - to prevent damage to the grid and equipment. That is what was done, and it was done rather well, just a few minutes before the grid collapsed. The rolling blackouts disfavoured poor areas since they didn’t have high priority establishments like hospitals amidst them.

Texas takes pride in having its own independent grid rather than be connected to the Eastern or Western grids. If they were connected, the state could have procured power from a larger grid to tide over the crisis. They couldn’t do that. 

The gas and oil equipment as well as windmills, which were designed for a warmer environment “froze”, more specifically the lubricants in them froze or became so thick and viscous that they simply shut down. The gas wells themselves “froze” thus reducing the gas output to nearly half of the regular levels.

Solar energy, a matter of pride for Texans, failed too since there was no sun and hence no output.

The overzealous alternate and renewable energy proponents had clearly not foreseen this. Renewables and alternate energy form a substantial part of the energy mix in the state. That a reliable baseload plan is unavoidable is a major lesson for all energy planners. Baseload comes primarily from coal, oil, gas, hydro, or nuclear sources, like it or not.

A permanent solution may take years coming.