From Express.co.uk this week comes news that a whole host of experts on eastern Europe have lined up to warn that the conflict in the eastern Ukraine could spark a widespread chemical disaster if industrial storage units of chlorine gas are damaged and the contents released into the environment.

The threat is not just hypothetical. On February 24 a stray artillery shell hit the Donetsk Filter Station’s chlorine gas depot, which stores around 7,000kg of the gas.

Fortunately, none of the storage units were damaged.

Robert Amsterdam, Russian political expert and lawyer at international law firm Amsterdam & Partners, said: “If one of those uncontrolled sites containing chemicals were to detonate, tens of thousands of people could be poisoned. It is a potential disaster on the scale of Chernobyl.”

Rudy Richardson, Professor of Toxicology at the University of Michigan backed up that view. He said: “In a situation like this, where a war zone is near a concentration of industrial facilities where toxic and explosive chemicals are manufactured and stored, it is possible that massive releases of toxic chemicals could occur.

“And that would result in high levels of civilian casualties.”

The United Nations Special Rapporteur on human rights and hazardous substances Basket Tuncak indicated that damage to just one chlorine-filled, 2,000-pound container has the potential to kill anyone within a 600-foot (200 metre) distance and poses dire health risks to the tens of thousands of surrounding residents.

In case of extensive damage, people living up to 4.5 miles (10km) downwind of the facility would need to be moved away within 24 hours.

Mr Tuncak told the UN: “Large chemical and industrial facilities are in areas where fighting is ongoing.

“Battles are now being fought in cities, close to industrial centres with factories increasingly at risk of being hit: The consequences for anyone living close by would be severe.”

He added: “All parties to the conflict need to be aware of the risks that continuous insecurity brings, including for a chemical disaster. Ultimately, it is about ensuring that all precautions are being taken to prevent such catastrophe to occur, and mainly for the fighting to stop.”

Clever technology coming out of Toronto, Canada, involves “insulated concrete forms”, or ICFs, (which) consist of two panels of Expanded Polystyrene foam, which are called EPS, with a hollow core in between. The panels are held tightly together by a patented web system, and can be stacked on top of each other in a way similar to Lego blocks,” says Keven Rector, Technical Services Manager at the company NUDURA.

These high-tech industry-leading forms have proven technologies to make building easier and faster, and are available in all form types and sizes, to accommodate all types of building and design requirements in times of disaster rebuilding. Each form is stacked, steel reinforced and filled with concrete to complete the building envelope of a home in one building step.

With their steel reinforced solid concrete core, these structures can withstand some of Mother Nature’s worst. NUDURA ICFs can endure winds of up to 400 kph and the non-toxic fire-retardant expanded polystyrene foam provides a fire protection rating of up to 4 hours, ensuring that your family and home are safe and secure in almost any situation.

The empty shells of expanded polystyrene foam can be put in place by hand, and once the “wall” has been built, filling the shell with concrete quickly surrounds the reinforcing steel holding the two panels together, and creates a solid weather-proof protection. Clever indeed!

And while we’re talking of clever protection, I heard today of a company in South Africa that has found a way to insert more or less invisible wiring into the transparent polycarbonate burglar bars becoming popular these days. The wires can be connected up into a mesh alarm system, such that sawing through, or burning the polycarbonate to gain entry to the building sets off the alarm, and makes a successful burglary unlikely. This is an extremely clever idea, protecting the contents of the building more effectively than the polycarbonate burglar bar on its own.

ARRL News reports that a thorough and fully annotated discussion of Near Vertical Incidence Skywave (NVIS) is available in the research paper, “Radio Communication via Near Vertical Incidence Skywave Propagation: An Overview,” by Ben A. Witvliet, PE5B/5R8DS, and Rosa Ma Alsina-Pagès.

First investigated in the 1920s, NVIS propagation was rediscovered during World War II as “an essential means to establish communications in large war zones such as the D-Day invasion in Normandy,” the paper notes, adding that the US Army subsequently sponsored a lot of NVIS field research, especially between 1966 and 1973. More recently, NVIS has become a popular means to enable close-in communication on Amateur Radio HF bands between 3 and 10 MHZ. NVIS can be used for radio communication in a large area (200-kilometer radius) without any intermediate manmade infrastructure, and it has been found to be especially suited for disaster relief communication, among other applications, according to the paper. Good reading for all amateurs expecting to erect an emergency station in the field.

Sadly, the dams in the Western Cape continued to drop their average content by another 2 percentage points, compared to last week, at 27%, and 6 percentage points lower than this time last year. The rest of the country’s dams are about the same as last week, or slightly higher, but none of them is in  a danger zone except the Western Cape. After some unusually hot weather this week, the Peninsula experienced 3 to 5mm of rain, which flattened the dust, but did nothing more. The evenings are cooler but any early frontal systems from the North-west continue to evade us!

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.

I didn’t realise last week how prophetic my words would be, when I wrote about the Cape Town Cycle Tour being subject to the mercies of the wind! Within twenty minutes of the first riders setting off from the Foreshore in Cape Town, the organisers had called the race off because of the dangerous South Easter whipping from the False Bay direction. You probably all saw the amazing videos of the bicycles floating like kites in the wind as the riders hung on to them for dear life. And if the front riders bailed out of their own volition because of the wind, you can imagine how difficult it would have been for the back riders, who are far less experienced, and less able to weather the headwind. Other endangering factors to the race were fires near the route in Hout Bay, and some risk to the riders from protesters down in the Southern Peninsula, which had already resulted in the organisers reducing the distance to about 74km. All in all, a wise decision by the organisers on a day of potential conspiring calamities, but bad luck indeed for the riders.

Roy Walsh ZS3RW wrote to tell of a simple incident in his neighbourhood that made him proud to be a HAMNET member. On Sunday 12 March, some fellows from the local clubs played cricket. One of the cricket players got hit by a bouncing cricket ball just above the eye. He should have had stitches but the medics at the field used steristrips and put them on his wound, which worked. After the game the guy wanted to clean his wound not knowing he should not have taken the plasters off.

“At church that evening I saw the wound still bleeding and because he did not have a medical aid I said I would contact someone and this is where the greatness of being a member of HAMNET came in” said Roy.

“I (ZS3RW) called Kobus Jooste ZS3KJ who is also a Paramedic at a local mine. He was very helpful and came to my house where he treated the young lad and off he went. The price? A great cup of coffee that I made for him (ZS3KJ) and his wife. This to me was just something that made me proud to say I am a member of HAMNET, where we could help someone.” Thanks for that Roy, and for being considerate.

From the Malagasy Daily Nation, comes the report that Madagascar has declared a national disaster after last week’s cyclone tore through the northern and eastern parts of the Indian Ocean island, leaving 78 dead and destroying thousands of homes.

According to the country’s National Bureau for Risks and Hazards Preparedness, Cyclone Enawo affected more than 390,000 people with 246,987 left homeless, 18 missing and 250 injured.

Madagascar’s President, Hery Rajaonarimampianina has asked for support from the international community. The Malagasy leader has been visiting the storm-hit areas to offer condolences and show support. He said the government will release a document that will highlight the issues in need of urgent relief.

Meanwhile, a cargo flight carrying 100 tonnes of humanitarian supplies from the United Arab Emirates arrived in the capital Antananarivo on Monday night. The aid includes medicine, food, and shelter kits which will be handed to the Malagasy government by the United Nations. Madagascar, a nation of an estimated 23 million people, has been hit by 46 natural disasters over the last 35 years.

And, for those who don’t live in Durban, the beachfront there was hit by storm-surge type waves on the 12th of March, as a side effect of Madagascar’s Cyclone, which finally spent its last energy on the KZN coast. The waves were not very high, but certainly washed across the front rows of car parking, and up to the doorways of the beachfront restaurants and cafes. Fortunately, the surge was not severe, but evidence that Mother Nature had been hard at work relatively nearby!

In general, the state of the water reservoirs around the country is fairly stable, with all but 2 of the provinces recording increases in dam levels this week, compared with last week and this time last year. Free State levels are 35% higher than this time last year, Gauteng and Kwazulu Natal 5%, Limpopo and Mpumalanga 19%, and North West and Northern Cape at least 40% more than last year. At 63%, the Eastern Cape is 10% down on last year, but the poor old Western Cape is 6% less than last year, at 29%. The situation here is becoming critical, because, apart from potable water for the population, water for industrial and commercial use will soon have to be restricted. Drinking water can always be brought in by tanker, or in bottles for consumers, but thousands of litres for factories and commercial users are harder to import. I wonder whether anyone in the world has considered the idea of building a desalination plant on a ship, which can sail from port to port, and provide emergency supplies where needed. The disadvantage apparently of a desalination plant is that it’s technology and catalytic materials deteriorate and it becomes a liability for the country to which it belongs, if it is not used all the time. Now a floating desalination plant could sail the seas and be used more or less continuously, thus “paying for itself”, so to speak.

Anybody got a couple of hundred million lying around unused, for us to corner this market?

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.

News from Madagascar is that Tropical Cyclone Enawo-17 has blown itself out in to the Southern Indian Ocean, and been downgraded to a Tropical Depression. Its worst day was Thursday the 9th, when close to 1,6 million people were suffering winds of the order of 230kph as Enawo chiselled its way down central Madagascar. Fortunately, advance warning and precautionary planning seems to have prevented a major loss of life and limb, and the country now scrambles to count the cost.

A message received from Roy Walsh ZS3RW of HAMNET Northern Cape announces that the new HAMNET banners crafted for all the divisions have been completed and are ready for distribution. Some 40 banners were ordered by the various divisions, and there remains only to distribute them to all corners of the country. So be on the lookout at the next HAMNET-supported event in your Province for sight of our new brand-labelling. We think they’re pretty smart.

Today sees the Cape Peninsula inundated with some 35000 cyclists riding their hearts out during the Cape Town Cycle Tour, perhaps better known formerly to the populace as “The Argus”! A mild sunny day with maximum temperature of 23 has been forecast, but as always, it is going to be the wind that makes or breaks the race. Riding into or away from a South-Easter or North-Wester has the ability to knock the stuffing out of riders, and the sweep vehicles are sometimes kept very busy. We’ll let you know next week if anything interesting arises as a result of weather conditions.

HAMNET Western Cape is also gearing up for the Old Mutual Two Oceans Marathon, taking place on Easter Saturday, the 15th April. Sixteen operator volunteers are needed to man the route by HAMNET, and all the Usual Suspects are encouraged to contact the bulletin reader soon with their intention to participate. Grateful thanks to all who do volunteer every year.

And, in a small potential disaster you may have missed, researchers at the Catalina Sky Survey in Arizona spotted a small asteroid as it came very close to Earth last Thursday week. Asteroid 2017 EA, which is smaller than 3 meters across (not much bigger that your double bed) passed within 14,500 kilometres of Earth on the morning of March 2. That distance is closer than several communication and weather satellites and about one-twentieth the distance of Earth to our Moon.

Sadly, according to a statement from NASA’s Centre of Near-Earth Object Studies (CNES), 2017 EA won’t be back for at least another 100 years. So you can put up your tower and Yagi without fear that it will be knocked down any time soon.

Software Defined Radio, or SDR, technology is going to be the way of the future. The days of superheterodyne receivers with two intermediate frequencies, and mixers, will soon be over, as the technology of software processing, with Field Programmable Gate Arrays, takes over. Several radio manufacturers already provide transceivers in which ordinary received signals are digitized, and fed through a chain of software manipulations, before being converted back to analogue signals, and fed to an audio amplifier for us to listen to. In reverse order, the microphone audio is digitized, and manipulated or equalised to suit the voice of the operator, before being converted to an analogue signal and transmitted via the antenna. All the digital stuff in between then gets managed by software on an attached computer or hardware in the radio itself. There is then almost no restriction on the number of manipulations possible. All you do is update the firmware of the chip in the radio.

Presumably miniaturisation will follow, as only the power modules need to be very big to put out the customary 100 watt signal.

Well, why not have the whole radio on a single chip, you ask? Mainly because the transmitted signal will destroy the receiver on the single chip each time you transmit. Not quite true anymore. Peter Dekker, ZS1PDE, has sent me an item from ECN, discussing the Transceiver on a Single Chip. In essence it goes like this.

Two-way communication requires, of course, both send and receive capabilities. But putting them in the same device requires a filter between the send and receive circuits to provide signal isolation.

Without a significant filter, communication would be impossible.

“Your transmit signal is 10¹⁴ times stronger than your receive signal,” said Alyosha Molnar, associate professor of electrical and computer engineering (ECE). “That’s 100 trillion times stronger – that’s a really hard problem.”

But researchers in Molnar’s lab have offered up a solution.

Molnar and collaborator Alyssa Apsel, professor of ECE, have devised a method for both transmitting and receiving a radio signal on a single chip, which ultimately could help change the way wireless communication is done.

Their work is described in “A wideband fully integrated software-defined transceiver,” published online Jan. 27 in the Institute of Electrical and Electronics Engineers’ Journal of Solid-State Circuits.

Separating the send and receive bands is difficult enough, but Molnar and Apsel have come up with an ingenious way of doing so. Their idea lies in the transmitter – actually a series of six sub-transmitters all hooked into an artificial transmission line. Each sends its signal at regular intervals, and their individually weighted outputs are programmed so that they combine to produce a radio frequency signal in the forward direction, at the antenna port, while cancelling out at the receive port.

The programmability of the individual outputs allows this simultaneous summation and cancellation to be tuned across a wide range of frequencies, and to adjust to signal strength at the antenna.

“In one direction, it’s a filter and you basically get this cancellation,” Apsel said. “And in the other direction, it’s an amplifier.”

“You put the antenna at one end and the amplified signal goes out the antenna, and you put the receiver at the other end and that’s where the nulling happens,” Molnar said. “Your receiver sees the antenna through this wire, the transmission line, but it doesn’t see the transmit signal because it’s cancelling itself out at that end.”

Very clever indeed! We hope this technology will not be long in being launched, and that emergency communications will greatly benefit from its ingenuity.

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.

News this week centres on weather, in all its forms and manifestations.

The City of Cape Town is considering additional plans to intensify level 3 water restrictions, amid a bid to declare the City an emergency disaster area.

Earlier, Cape Town Mayor Patricia De Lille, announced plans to write to the environmental affairs MEC to declare Cape Town an emergency disaster area.

Briefing media and other parties, De Lille said the City is in a crisis, with the average dam levels now at 33%.

Dr Kevin Winter of the Future Water Institute was at the briefing.

Short and medium term plans have so far helped reduce water consumption in the city – decreasing water consumption by 27%.

Further water restrictions will likely in the near future include no irrigation and no topping up of swimming pools.

Winter says he is impressed by the comprehensive approach that the city has taken in addressing the issue.

It brought home two realities – the water crisis and the intent of the City to write to Minister Anton Bredell to declare Cape Town a disaster.

“The other wake-up call is the recognition that we now need to be much more proactive in the way in which we are integrating our water sources and the different sources that we need to call on in the near future.

There is still no clarity whether there is funding to continue with the implementation of the Table Mountain Group (TMG) aquifer scheme between 2022 and 2026.

I would hope to see at some stage – if we are bringing it forward – what those timelines and planning are all about because it’s certainly not in any City budget that I have seen so far,” said Dr Kevin Winter, Future Water Institute researcher.

Winter says the rainfall predictions remain uncertain, but control of water use needs to be tightened.

De Lille is hoping national government will free funds to enable the municipality to implement new water supply schemes.

Globetrotting surfing pro Dion Agius was touring in Mozambique earlier this month, and so was Cyclone Dineo, smashing Mozambique and Zimbabwe, flooding huge swaths of both countries. Over 100,000 people were displaced in Mozambique, with dozens of homes destroyed and at least seven people killed.

The storm caught Agius by surprise, and as he waited out the storm’s passing, he recorded his lodging being ripped apart by 180 km/hr winds. He was so moved by the destruction he saw the next day that he put together a short film to help spread the word that the locals need help.

Very little outside media is reporting on the disaster. Some South African news agencies as well as Al Jazeera have done stories but word doesn’t seem to be spreading to the rest of the world.

Agius is drawing people’s attention to a GoFundMe campaign, if they’re inclined and have the means to help these people rebuild.

And, in Zimbabwe, floods have killed 246 people and left nearly 2,000 homeless since December, government officials said.

Aljazeera News reports that Saviour Kasukuwere, minister of local government, declared a national disaster and announced the death toll on Thursday, saying 128 people have been injured in the floods.

The Southern African country has appealed to international donors for $100m to help those affected by the floods, which have washed away several bridges and roads and cut off some communities from surrounding areas.

“There is an inadequate supply of tents, foodstuffs and drugs for the affected people,” Kasukuwere told The Herald newspaper. “There is a need for blankets and clothing for the affected families as they are at risk of contracting pneumonia and acute respiratory infections.”

Unable to get balance of payment support from foreign lenders due to unpaid arrears, and with more than 90 percent of its national budget going to salaries, Zimbabwe’s public infrastructure has been crumbling for more than a decade.

“After working hard responding to the effects of drought, the same people are now suffering because of excessive floods,” Bishow Parajuli, of the United Nations Development Programme (UNDP), told The Herald.

Transport Minister Joram Gumbo told reporters on Wednesday that in the southern parts of the country, some sections of highways and bridges were completely washed away following the latest heavy rainfall.

Gumbo said the government would raise $100m to repair the country’s infrastructure. The national road agency would chip in with half of the money, which it would borrow from local banks, he said.

“The state of our roads has further deteriorated to the extent that some sections of the national road network have become impassable,” Gumbo said.

And, if that isn’t enough, there is another tropical storm lurking on the far side of Madagascar, this one called Enawo, forecast to strike Madagascar as an intense tropical cyclone at about 06:00 UTC on Tuesday 7 March. Enawo is expected to bring 1-minute maximum sustained winds to the region of around 203 km/h. Wind gusts in the area may be considerably higher.

According to the Saffir-Simpson damage scale, the potential property damage and flooding from a storm of Enawo’s strength (category 3) at landfall includes: storm surge generally 2.7-3.7 metres (9-12 feet) above normal; some structural damage to small residences and utility buildings;  damage to shrubbery and trees with foliage blown off trees and large trees blown down; mobile homes and poorly constructed signs destroyed; and low-lying escape routes cut by rising water 3-5 hours before arrival of the centre of the storm. Flooding near the coast may destroy smaller structures with larger structures damaged by battering from floating debris. Terrain may be flooded inland for 13 km or more. Evacuation of low-lying residences within several blocks of the shoreline may be required. There is also the potential for flooding further inland due to heavy rain.

At this stage, it looks as though Enawo will remain East of Madagascar, so South Africa should be safe, but weather-watchers on our Eastern coastline are advised to remain vigilant.

Thank you to the national and international news agencies for these news items.

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.