Wednesday, June 7, 2023

SAS: Great Escapes (Benghazi 1942)

The man who went to war without a gun: How SAS medic won Military Cross for saving the lives of comrades in aftermath of disastrous 'Operation Bigamy' Libya raid in WWII

  • Malcolm Pleydell was the SAS's first ever doctor, joining in June 1942
  • He treated the wounded after attempt to attack Benghazi failed disastrously 
  • Pleydell played vital part in shepherding the men more than 600 miles to safety 

He was the man who went to war without a gun, but still saved his comrades from certain death. 

Malcolm Pleydell was the first ever doctor to join the SAS after its formation by Lieutenant-David Stirling in 1941, and won the prestigious Military Cross for his efforts.

He played a vital part in the aftermath of the disastrous 'Operation Bigamy' raid on Italian-held Benghazi in September 1942, which 'sinned against just about every founding precept of the SAS', according too historian Damien Lewis.

The story of Pleydell and his heroics is revealed in Mr Lewis's new book SAS Great Escapes II, which was released last month. 

The book reveals how he saved the lives of several gravely wounded men in his care, before shepherding dozens of other less severely injured men more than 600 miles across largely open desert to safety as they were repeatedly attacked by enemy planes.

But he also had to cope with the tragic loss of four of the most seriously wounded, after they had to be left behind near Benghazi because there was no space to carry them. 

Another man, whose nickname was 'Razor Blade', perished too after losing a coin toss and having to stay with the injured in the hope the enemy would treat them. 

According to Pleydell's Military Cross citation, he 'attended to the wounded without any thought of his own safety,' including removing a bullet from one man's thigh as a German plane circled overhead.

Malcolm Pleydell was the first ever doctor to join the SAS after its formation by Lieutenant-David Stirling in 1941, and won the prestigious Military Cross for his efforts. Above: Pleydell (centre with cigarette) is seen with his SAS comrades

Malcolm Pleydell was the first ever doctor to join the SAS after its formation by Lieutenant-David Stirling in 1941, and won the prestigious Military Cross for his efforts. Above: Pleydell (centre with cigarette) is seen with his SAS comrades

His daughter Alison Smartt, 73, only recently discovered the extent of Pleydell's exploits after reading Mr Lewis's book.

She told MailOnline: 'I always was very proud of him, but the more I learn about him I am in awe.' 

Speaking last month at the launch of his book, Mr Lewis said: 'In Operation Bigamy, they were ordered to go in with around about 200 men and a massive column of vehicles including two Matilda tanks and basically cross the whole of the desert to a rigid timescale to attack Benghazi,' he said.

'As they predicted, it was an utter disaster.'

'The compelling thing about the Malcolm Pleydell story was that now here's a man who you could argue, I guess his bravery was greater than anybody else, because he wasn't there with the gun, he couldn't defend himself,' he added.

'It's something that maybe I relate to very closely because I was a war reporter for 20 years, so I've been on the front line, but with a camera, not with a gun.

'It's a strange thing to have to do when you can't fight back. So he was in that same situation.'

The aim of Operation Bigamy had been to punch through Benghazi's defences, seize the city's port and blow up as much enemy shipping as possible.

They also aimed to destroy infrastructure at the harbour, attack any nearby airfields and even cut the undersea cable linking the Benghazi base to Italy.

The raiders split up into two groups. Stirling and legendary commander Paddy Mayne - a close friend of Pleydell's - spearheaded the thrust into Benghazi itself, whilst Melot took a smaller party to destroy the city's radio outpost.

Pleydell played a vital part in the aftermath of the disastrous 'Operation Bigamy' raid on Italian-held Benghazi in September 1942, which 'sinned against just about every founding precept of the SAS', according too historian Damien Lewis

Pleydell played a vital part in the aftermath of the disastrous 'Operation Bigamy' raid on Italian-held Benghazi in September 1942, which 'sinned against just about every founding precept of the SAS', according too historian Damien Lewis

The SAS's founder, Lieutenant-Colonel David Stirling
Paddy Mayne, Stirling's second in command

The SAS's founder, Lieutenant-Colonel David Stirling (left) and his second in command Paddy Mayne (right) were part of the Operation Bigamy raid

Meanwhile, the RAF would launch a raid on Benghazi to try to divert attention away from the SAS's attack.

How bored SAS medic joined famed unit to experience something 'new and so entirely uncertain'

Pleydell's parent unit had been the Royal Army Medical Corps (RAMC). 

During the evacuation of British troops from Dunkirk in 1940, he was serving as a doctor on a pleasure steamer which ferried some of the men to Dover.

A thousand injured men ended up crammed into the ship's dining salon 'like sardines', as he later recalled. 

He and the casualties then had to endure the chaos of the moment the steamer collided with a British destroyer, leaving the men in a 'jumbled heap'.

Fortunately, the ship had been holed above the water line and so was able to limp into port with its cargo of wounded men. 

In the spring of 1942, Pleydell was deployed to North Africa to serve as a medic with the Coldstream Guards. 

The diary he kept during that time recorded various skirmishes with German forces. After one, he wrote: 'Thought my last time of freedom had come... position seemed hopeless... Dusk came to our rescue ... Moved through German lines ... Very frightening day ... Seemed certain we were going to be put in the bag.'

The closest he came to being directly wounded was when a lump of shrapnel ripped a hole through his jacket. 

He opted to join the SAS in June 1942 - despite knowing very little about the secretive unit - due to a sense of frustration at his then role as a doctor at a military hospital.

Bored, he decided to sign up for something 'new and so entirely uncertain.' 

He initially linked up with Stirling's unit in Kibrit, Egypt, and described the set-up as 'something like out of one of those absurd thrillers.'

Pleydell and Mayne immediately struck up a good relationship, due in part to the fact that both men were, in the words of Mr Lewis, 'well-read, erudite, cultured.' 

Both men were also drawn to boxing and rugby, although Pleydell was not at the level of Mayne in the latter, who had played for Ireland and the British Lions.

After their departure, Pleydell focused on moving his jeep and a medical truck so that they could be camouflaged against strikes from the air.

The first sign of trouble came when one of the raiders' jeeps returned. The driver told Pleydell that Melot and a second man, Captain Chris Bailey, had been badly injured.

Pleydell had to strip off the camouflage netting obscuring his team's vehicles and immediately followed the jeep to where 'ashen-faced' Melot lay.

The Belgian had been caught in the blast of one of his party's own hand grenades and was peppered with shrapnel from the abdomen down.

Despite the serious injuries that he and Bailey had suffered, Melot's raid on the wireless station had largely been a success.

But the man himself urgently needed a blood plasma and a dose of morphine, with further treatment to come later.

Bailey had a tiny hole above his heart. His left lung had collapsed and he was struggling to breathe.

As Pleydell began treating Melot, what he described as a 'fast crackle of machine-gun fire' burst through the air.

The men were under attack from enemy planes overhead. Pleydell did his best to further camouflage his men and patients as machine gun fire peppered the ground nearby.

After the threat subsided, the first of the injured men from Benghazi arrived. A jeep was carrying a man in so much pain that he was pleading: 'Chop off this bloody arm, for God's sake!'

Pleydell administered a shot of morphine, but more injured quickly arrived – although most had relatively minor flesh wounds.

It then emerged how the Benghazi attack force had been bombarded with mortars, machine guns and Breda 20mm cannons after getting near the city.

A jeep carrying the explosives intended for the harbour attack was blown to pieces.

Although Stirling and Mayne managed to initially flee the barrage with their men, they then came under fierce bombardment from the air as they tried to make it back to the cover of the hills.

Fortunately, they reached Pleydell without any further losses. Now the team faced the hellish prospect of having to travel across more than 600 miles of desert to the relative safety of the Kufra Oasis, whilst carrying the wounded with them.

That night's drive was, according to Pleydell, a 'wretched affair', as the bumps and jolts of the vehicles caused the injured men to cry out in pain.

'Asleep? Awake? The two had merged together,' Pleydell wrote.

At 3am, they reached relative safety and so set up camouflage netting and set down to sleep.

Then the team were plagued by rumours that they had been encircled by 5,000 Italian troops. 

Pleydell had to contend with the potential consequences of that as he further assessed the wounded.

One man, Sergeant Eustace Sque, had been shot in the leg, the bullet smashing his femur. 

Another, Sergeant James Webster, needed to have his leg amputated by the doctor in the open desert after being wounded in a mine blast.

A third soldier had a shattered arm, whilst Bailey – whose lung was punctured – had worsened overnight.

Then, Pleydell was alerted to yet another wounded man who just been found.

Pleydell's parent unit had been the Royal Army Medical Corps (REMC). During the evacuation of British troops from Dunkirk in 1940, he was serving as a doctor on a pleasure steamer which ferried some of the men to Dover

Pleydell's parent unit had been the Royal Army Medical Corps (REMC). During the evacuation of British troops from Dunkirk in 1940, he was serving as a doctor on a pleasure steamer which ferried some of the men to Dover

Pleydell's SAS medical team are seen above. The men helped him care for the wounded

Pleydell's SAS medical team are seen above. The men helped him care for the wounded

Corporal Anthony Drongin, who was lying several miles from the main convoy, needed urgent surgery.

As Pleydell tried to operate, enemy warplanes kept appearing overhead, forcing him to repeatedly pause his vital work.

And in the time that he had been gone, the main convoy had been attacked from the air. 

Pleydell's Red Cross truck was among around 20 which had been destroyed, as the patients lay helpless.

Sergeant Sque had been shot through the same leg that was already injured, another man, Germain Guerpillon, was far more seriously wounded.

Pleydell noted how he was 'beyond any crude help I could provide'. The Frenchman died soon afterwards.

More wounded continued to emerge, even as the team also had to contend with the loss of tonnes of water, food, ammunition and fuel.

But then the real devastating news came from the lips of Stirling. There was not enough room in the remaining vehicles to carry the most gravely wounded men.

Drongin, Bailey, Webster and Sque would have to be left behind.

The team decided that the best option was for one fit man to stay with the wounded men and surrender to the enemy, in the hope that the Italians would take them as prisoners of war and treat them.

Pleydell insisted that he could stay with the injured, but Stirling and Mayne vetoed the proposal, telling him his skills were too crucial to the rest of the team.

Instead, a coin was tossed to determine which of the medical orderlies would stay behind.

Johnson, whose nickname was 'razor blade' due to his skill with a knife, was the man who lost the toss.

Pleydell felt an immense sense of guilt that he was leaving the men he so desperately wanted to care for.

After a final handshake with Johnson, who bravely said, 'someone had to stay, sir,' the remainder of the convoy moved off.

They faced a journey back to Kufra across open desert, whilst contending with the near-constant threat of attack from the air.

The only cover was the odd shallow patch of vegetation, where the convoy would pause to rest.

To make matters worse, the team's rations had been depleted to just one bottle of water per man per day, with meagre portions of food in the evening.

They would also not be able to make it back unless they secured fresh supplies of fuel.

Mayne decided break off from the convoy and travel a further 500km to Libya's Jalo Oasis in the hope it had been seized from the enemy by the Allies.

There, he might get fuel supplies which he could bring back.

Stirling meanwhile opted to stay in the Jebel with a handful of men and three jeeps, to search for stragglers and the missing.

Pleydell was left to carry the burden of caring for the wounded, as they continued to come under attack.

Lewis writes: 'The day dragged on, and the enemy came hunting in their droves. Sometimes, the warplanes passed so low overhead that the pilot's face was clearly visible.

'The sun rose higher. The shade dissipated. The heat crawled and clawed. No one could risk the slightest move.'

When sundown came, the convoy continued moving. With them was expert navigator Mike Sadler, who used a sextant to observe the stars and ensure they were on the right track.

Expert navigator Mike Sadler (left), now the only survivor from the original SAS, is seen with David Stirling in the desert

Expert navigator Mike Sadler (left), now the only survivor from the original SAS, is seen with David Stirling in the desert

By September 18, Sadler - who is now the only surviving member of the original SAS after the death Lance Corporal Alec Borrie last month - reckoned it was safe enough to travel in the day.

As they neared the Jalo Oasis, the sound of distant artillery fire signified that it was still under siege by the Allies.

The team decided to send a scouting party led by recent SAS recruit Lieutenant James 'Sandy' Scratchley up ahead to see if they could find any fuel, and perhaps come across Mayne and his crew.

However, as the night drew on and Scratchley's team failed to return, Pleydell feared they had been lost.

Melot meanwhile was being plagued by swarms of ants, which nibbled at the dried blood caking his injuries.

By nightfall the following day, Scratchley and his party had still not appeared, and so experienced officer Lieutenant Bill Frazer volunteered to go and look for them.

Three hours later, Frazer returned with news that the Allies had failed to take Jalo, because, like in Benghazi, the Italians had known they were coming.

It also emerged that Mayne had reached Jalo and had since been ordered to withdraw.

Scratchley and his men had become trapped in no-man's-land, pinned down by fire from both directions.

However, the crucial fuel supplies had been secured by Mayne, so Frazer immediately went to seize them.

Once refuelled, the party decided to wait until nightfall to carry on.

Fortunately, the terrain had significantly improved, to the extent that even the trucks carrying the most gravely wounded could average 30-40mph.

They soon arrived at Bir Zighen, the site of a cache of hidden supplies. 

'I fear we all made pigs of ourselves,' Pleydell confessed in his diary as the men stocked up on food and water.

At Bir Zighen too was Force Z of the British Sudan Defence Force, which had been engaged in the battle for Jalo.

There was further respite in the form of a message from command, telling them that 15 ten-tonne trucks had been dispatched to a nearby makeshift airstrip.

An aircraft too was being sent to collect the wounded and deliver ammunition.

During their escape from the area around Benghazi, the team had to contend with the hardships of the open desert. Above: SAS soldiers dig their jeep out of the sand

During their escape from the area around Benghazi, the team had to contend with the hardships of the open desert. Above: SAS soldiers dig their jeep out of the sand

Pleydell's medical jeep is seen burdened with supplies as it travels through the desert

Pleydell's medical jeep is seen burdened with supplies as it travels through the desert

Pleydell opted to leave Macleod and Melot with Force Z's doctor, so they could be picked up by the RAF. 

He then set off again towards Kufra with the original SAS convoy.

Finally, at dawn the following day, the green smudge of the Kufra Oasis appeared on the horizon.

The men, both fit and wounded, had survived their remarkable escape across the desert.

However, not long after pulling into the SAS's encampment at Kufra, the enemy launched one final attack.

Fortunately, the SAS patrols – protected by the tall palm trees – survived largely unscathed by the bullets and bombs of the Heinkel He 111 planes, around half of which were shot down by anti-aircraft guns.

Stirling meanwhile had managed to round up some of the dozens of missing men. 

SAS Great Escapes II, by Damien Lewis, is published by Quercus

SAS Great Escapes II, by Damien Lewis, is published by Quercus

He later wrote: 'I lost about 50 three-tonners [trucks] and about 40 jeeps on this raid but fortunately not very many personnel...It was a sharp lesson that confirmed my previous views...'

Melot was among those who made a full recovery from his injuries. A little over three months later, he was back on active duty.

He continued to serve with the SAS until he was killed in an accident in his jeep in Belgium in November 1944.

However, medical orderly Johnson and his wounded charges of Bailey, Sque, Webster and Drongin were all killed in Benghazi – although their exact fate remains a mystery.

The hope that the enemy would take them in as PoWs had proved to be tragically unfounded, and the loss proved to be an immense burden for Pleydell.

After the debacle, he and Mayne took a weekend's leave together in Cairo, where their bonds deepened.

Writing home, he told how the commander was 'now my squadron leader and a Major, and I'm damn glad I'm with him.

'You can rely on him 100% to get you out of anywhere if things look a bit sticky.'

Pleydell ultimately decided to give up his medical duties in the SAS in 1943 after becoming exhausted by the 'mental strain' of caring for the wounded.'

He was hospitalised for a year and never returned to active duty.

Mr Lewis added: 'Pleydell very badly traumatised by what he had been through - as were many of these men - so it's a really compelling tale of the responsibility and the toll it takes on a man who goes to war not to fight but to save lives.'

After the war, Pleydell married wife Jeanette (above, the pair on their wedding day) and worked as a public health officer
The doctor in later life

After the war, Pleydell married wife Jeanette (above, the pair on their wedding day) and worked as a public health officer. Right: The doctor in later life 

The citation accompanying his Military Cross pays a fitting tribute, telling how he 'undoubtedly saved many lives by his bravery and skill'. 

After the war, Pleydell married wife Jeanette and worked as a public health officer.

Along with their daughter Alison, they had son John. Pleydell passed away aged 86 in 2001.

Ms Smartt said: 'We had the most happy, fabulous, wonderful childhood. My father was enormous fun.

'But he was very quiet on occasion. When he came back from work, it was always understood that we left him for an hour and a bit where he would put on classical music and wind down.'

She added: 'He wouldn’t talk about his war experiences at all. I've learnt more from Damien than anybody else.' 

Tuesday, June 6, 2023

HeartBEiT: Mount Sinai’s AI Innovation Decoding Electrocardiograms As Language

Mount Sinai Hospital, Mount Sinai School Of Medicine

HeartBEiT is much more precise at highlighting areas of interest, in this case for diagnosing heart attacks (myocardial infarction). 
Credit: Augmented Intelligence in Medicine and Science Laboratory at the Icahn School of Medicine at Mount Sinai

Mount Sinai’s AI model, HeartBEiT, improves the accuracy and detail of ECG diagnoses, even for rare conditions with limited data. It interprets ECGs as language and outperforms traditional CNNs, highlighting specific ECG areas responsible for heart conditions.

Mount Sinai researchers have developed an innovative artificial intelligence (AI) model for electrocardiogram (ECG) analysis that allows for the interpretation of ECGs as language. This approach can enhance the accuracy and effectiveness of ECG-related diagnoses, especially for cardiac conditions where limited data is available on which to train.

In a study published in the June 6 online issue of npj Digital Medicine, the team reported that its new deep learning model, known as HeartBEiT, forms a foundation upon which specialized diagnostic models can be created. The team noted that in comparison tests, models created using HeartBEiT surpassed established methods for ECG analysis.

“Our model consistently outperformed convolutional neural networks [CNNs], which are commonly used machine learning algorithms for computer vision tasks. Such CNNs are often pretrained on publicly available images of real-world objects,” says first author Akhil Vaid, MD, Instructor of Data-Driven and Digital Medicine (D3M) at the Icahn School of Medicine at Mount Sinai. “Because HeartBEiT is specialized to ECGs, it can perform as well as, if not better than, these methods using a tenth of the data. This makes ECG-based diagnosis considerably more viable, especially for rare conditions which affect fewer patients and therefore have limited data available.”

Thanks to their low cost, non-invasiveness, and wide applicability to cardiac disease, more than 100 million electrocardiograms are performed each year in the United States alone. Nonetheless, the ECG’s usefulness is limited in scope since physicians cannot consistently identify, with the naked eye, patterns representative of disease, particularly for conditions which do not have established diagnostic criteria or where such patterns may be too subtle or chaotic for human interpretation. Artificial intelligence is now revolutionizing the science, however, with most of the work to date centered on CNNs.

Mount Sinai is taking the field in a bold new direction by building on the intense interest in so-called generative AI systems such as ChatGPT, which are built on transformers—deep learning models that are trained on massive datasets of text to generate human-like responses to prompts from users on almost any topic. Researchers are using a related image-generating model to create discrete representations of small parts of the ECG, enabling analysis of the ECG as language.

“These representations may be considered individual words, and the whole ECG a single document,” explains Dr. Vaid. “HeartBEiT understands the relationships between these representations and uses this understanding to perform downstream diagnostic tasks more effectively. The three tasks we tested the model on were learning if a patient is having a heart attack, if they have a genetic disorder called hypertrophic cardiomyopathy, and how effectively their heart is functioning. In each case, our model performed better than all other tested baselines.”

Researchers pretrained HeartBEiT on 8.5 million ECGs from 2.1 million patients collected over four decades from four hospitals within the Mount Sinai Health System. Then they tested its performance against standard CNN architectures in the three cardiac diagnostic areas. The study found that HeartBEiT had significantly higher performance at lower sample sizes, along with better “explainability.” Elaborates senior author Girish Nadkarni, MD, MPH, Irene and Dr. Arthur M. Fishberg Professor of Medicine at Icahn Mount Sinai, Director of The Charles Bronfman Institute of Personalized Medicine, and System Chief, Division of Data-Driven and Digital Medicine, Department of Medicine: “Neural networks are considered black boxes, but our model was much more specific in highlighting the region of the ECG responsible for a diagnosis, such as a heart attack, which helps clinicians to better understand the underlying pathology. By comparison, the CNN explanations were vague even when they correctly identified a diagnosis.”

Indeed, through its sophisticated new modeling architecture, the Mount Sinai team has greatly enhanced the manner and opportunities by which physicians can interact with the ECG. “We want to be clear that artificial intelligence is by no means replacing diagnosis by professionals from ECGs,” explained Dr. Nadkarni, “but rather augmenting the ability of that medium in an exciting and compelling new way to detect heart problems and monitor the heart’s health.”

The paper is titled “A foundational vision transformer improves diagnostic performance for electrocardiograms.”



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Monday, June 5, 2023

A New Iron Age: Metal Fuel for Carbon-Free Energy on Earth… and the Moon

By EUROPEAN SPACE AGENCY (ESA) JUNE 4, 2023

Scientists have conducted research on discrete burning, a form of fire that jumps from one fuel source to another, using iron powder in zero gravity. The leftover product after combustion is iron oxide, a substance that doesn’t produce carbon dioxide and can be endlessly recycled. 
Following these microgravity experiments, efficient iron-burning furnaces have been developed, leading to the creation of a circular, carbon-free energy storage. 
A demonstration plant is operational in The Netherlands, and multiple start-ups are exploring this carbon-free fuel for factories and industrial processes. Looking ahead, this metal fuel could also be used for sustainable lunar outposts, potentially using lunar minerals and ice to produce metallic powders for propulsion and water for consumption.
 Credit: Iron+

Researchers have utilized microgravity experiments to study discrete burning of iron powder, leading to carbon-free, endlessly recyclable energy storage. This has promising applications on Earth and for future sustainable lunar outposts.

Everything burns. Given the right environment, all matter can burn by adding oxygen, but finding the right mix and generating enough heat makes some materials combust more easily than others. Researchers interested in knowing more about a type of fire called discrete burning used ESA’s microgravity experiment facilities to investigate.

In a series of parabolic flights and on sounding rockets launched from Sweden, a team from Professor Jeffrey Bergthorson at McGill University in Canada and Eindhoven University of Technology in The Netherlands investigated burning iron powder in zero gravity. Their research was pure physics, the scientists wanted to know more about discrete burning whereby flames do not burn through fuel continuously but jump from one fuel source to another. This form of fire hardly occurs naturally on Earth, but an example is a forest fire where one tree burns completely and the fire jumps to the next tree when the temperature increases enough for combustion.

This hypnotic video of discrete burning was recorded during a parabolic flight experiment on board the Falcon-20 aircraft of the Canadian National Research Centre that offers researchers up to eighteen seconds of precious zero-gravity. 
Credit: Perwaves team


Burning iron dust in experiments on zero-g aircraft and rocket flights allowed for the iron particles to float and ignite discreetly. High-speed cameras captured the spectacle and allowed the researchers to better understand the phenomenon, resulting in computer models that showed the ideal conditions to burn the fuel on Earth.

Did you know iron could burn? The combustion of iron powder seen here is taking place on an entirely smokeless, carbon free basis. 
Credit: TU/e / Solid / Bart van Overbeeke



Discrete burning for sustainable energy

With the new understanding made possible from microgravity research, it became possible to build efficient and practical iron-burning furnaces.

The advantage of burning iron is down to chemistry. Essentially, burning fuel is the process of transforming a material by adding oxygen atoms. This is why carbon-based fuel produces the greenhouse gas carbon dioxide when two oxygen atoms are added to the carbon-based fuel such as wood, coal, or oil. With iron, the leftover product after combustion is iron oxide, more commonly known as rust. No carbon dioxide is produced, and the rusty iron can be easily collected as it doesn’t form a gas – burning iron emits no noxious gases at all.

Iron rust can even be processed to remove the oxygen and return it as iron using hydrogen. By using electricity from sustainable sources, iron as a fuel can become a circular, endlessly recyclable energy storage.

A demonstration plant is already up and running in Budel, near Eindhoven, The Netherlands, using iron as its fuel source this generator can produce 1 MW of steam in a unit that stands in a warehouse. Scaled up such an iron power plant could produce much more energy.

Multiple start-ups are already pursuing this carbon-free fuel, to power factories and industrial processes.

Iron furnace demonstration plant. 
Credit: Metalot
From space to Earth and then to the Moon

As space agencies prepare to build sustainable lunar outposts, supplying energy for the astronauts on the Moon is just one of the challenges to overcome. Metal fuel could be a solution. Using solar energy, not only aluminum and silicon powders can be produced from lunar minerals, but also hydrogen and oxygen can be harnessed from lunar ice.. The hydrogen can then be used to convert lunar dust that is high in iron and titanium to produce water and iron powder. The metallic powders and oxygen from the water ice can be used as propellants for rockets or ground transportation and the water by-product can even be used as drinking water.

Artist’s impression of a Moon exploration scenario.
 Credit: ESA–ATG

This process might seem like science fiction now but using iron as a fuel source on Earth started out as an idea just a decade ago. Now the metal fuel community spans hundreds of scientists and engineers around the globe and is a lighthouse technology for alternative carbon-free fuel. In a not-so-distant future, you might be running your car or home on iron!

Metals could be produced using clean energy, such as from solar cells or wind turbines. That electricity is stored as chemical energy in the metal powder at energy densities that are competitive with fossil fuels. This has the potential to reduce greenhouse gasses emission globally, but a barrier to implementing this technology is the development of combustion systems that can efficiently burn the metal fuels, which requires a solid understanding of their combustion physics. 
Credit: ESA – European Space Agency




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Saturday, June 3, 2023

Mysterious dashes revealed in Milky Way's center

JUNE 2, 2023, by Northwestern U.

MeerKAT image of the galactic center with color-coded position angles of all filaments. 
Credit: Farhad Yusef-Zadeh/Northwestern University

An international team of astrophysicists has discovered something wholly new, hidden in the center of the Milky Way galaxy.

In the early 1980s, Northwestern University's Farhad Yusef-Zadeh discovered gigantic, one-dimensional filaments dangling vertically near Sagittarius A*, our galaxy's central supermassive black hole. Now, Yusef-Zadeh and his collaborators have discovered a new population of filaments—but these threads are much shorter and lie horizontally or radially, spreading out like spokes on a wheel from the black hole.

Although the two populations of filaments share several similarities, Yusef-Zadeh assumes they have different origins. While the vertical filaments sweep through the galaxy, towering up to 150 light-years high, the horizontal filaments look more like the dots and dashes of Morse code, punctuating only one side of Sagittarius A*.

The study will be published on Friday (June 2) in The Astrophysical Journal Letters.

"It was a surprise to suddenly find a new population of structures that seem to be pointing in the direction of the black hole," Yusef-Zadeh said. "I was actually stunned when I saw these. We had to do a lot of work to establish that we weren't fooling ourselves. And we found that these filaments are not random but appear to be tied to the outflow of our black hole. By studying them, we could learn more about the black hole's spin and accretion disk orientation. It is satisfying when one finds order in a middle of a chaotic field of the nucleus of our galaxy."

An expert in radio astronomy, Yusef-Zadeh is a professor of physics and astronomy at Northwestern's Weinberg College of Arts and Sciences and member of CIERA.

MeerKAT image of the galactic center with color-coded position angles of the short, radial filaments.
 Credit: Farhad Yusef-Zadeh/Northwestern University
Decades in the making

The new discovery may come as a surprise, but Yusef-Zadeh is no stranger to uncovering mysteries at the center of our galaxy, located 25,000 light-years from Earth. The latest study builds on four decades of his research. After first discovering the vertical filaments in 1984 with Mark Morris and Don Chance, Yusef-Zadeh—along with Ian Heywood and their collaborators—later uncovered two gigantic radio-emitting bubbles near Sagittarius A*. Then, in a series of publications in 2022, Yusef-Zadeh (in collaborations with Heywood, Richard Arent and Mark Wardle) revealed nearly 1,000 vertical filaments, which appeared in pairs and clusters, often stacked equally spaced or side by side like strings on a harp.

Yusef-Zadeh credits the flood of new discoveries to enhanced radio astronomy technology, particularly the South African Radio Astronomy Observatory's (SARAO) MeerKAT telescope. To pinpoint the filaments, Yusef-Zadeh's team used a technique to remove the background and smooth the noise from MeerKAT images in order to isolate the filaments from surrounding structures.

"The new MeerKAT observations have been a game changer," he said. "The advancement of technology and dedicated observing time have given us new information. It's really a technical achievement from radio astronomers."

A schematic diagram of the outflow from Sagittarius A*, the Milky Way's central supermassive black hole. 
Credit: Farhad Yusef-Zadeh/Northwestern University

Horizontal vs. vertical

After studying the vertical filaments for decades, Yusef-Zadeh was shocked to uncover their horizontal counterparts, which he estimates are about 6 million years old. "We have always been thinking about vertical filaments and their origin," he said. "I'm used to them being vertical. I never considered there might be others along the plane."

While both populations comprise one-dimensional filaments that can be viewed with radio waves and appear to be tied to activities in the galactic center, the similarities end there.

The vertical filaments are perpendicular to the galactic plane; the horizontal filaments are parallel to the plane but point radially toward the center of the galaxy where the black hole lies. The vertical filaments are magnetic and relativistic; the horizontal filaments appear to emit thermal radiation. The vertical filaments encompass particles moving at speeds near the speed of light; the horizontal filaments appear to accelerate thermal material in a molecular cloud.

There are several hundred vertical filaments and just a few hundred horizontal filaments. And the vertical filaments, which measure up to 150 light-years high, far surpass the size of the horizontal filaments, which measure just 5 to 10 light-years in length. The vertical filaments also adorn space around the nucleus of the galaxy; the horizontal filaments appear to spread out to only one side, pointing toward the black hole.

"One of the most important implications of radial outflow that we have detected is the orientation of the accretion disk and the jet-driven outflow from Sagittarius A* along the galactic plane," Yusef-Zadeh said.


MeerKAT image of the galactic center with color-coded position angles of the long, vertical filaments. 
Credit: Farhad Yusef-Zadeh/Northwestern University

'Our work is never complete'

The new discovery is filled with unknowns, and Yusef-Zadeh's work to unravel its mysteries has just begun. For now, he can only consider a plausible explanation about the new population's mechanisms and origins.

"We think they must have originated with some kind of outflow from an activity that happened a few million years ago," Yusef-Zadeh said. "It seems to be the result of an interaction of that outflowing material with objects near it. Our work is never complete. We always need to make new observations and continually challenge our ideas and tighten up our analysis."


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Friday, June 2, 2023

Shell beads discovery sheds light on Stone Age seafaring

MAY 30, 2023, by De Gruyter

Location of Kaylu archeological site (a no 1), Jebel (a no 2), and Dam-Dam-Cheshme 1 and 2 (a no 3); 
view of the rockshelter (b1); 
location of the two burials (b2 and b3); 
Caspian Sea view from the site (c); 
human remains state of preservation (d and e); 
lithic industry from layer 7 of Kaylu (f) – point (1), lunates (2, 3), end-scraper (4), splinted pieces (5, 6), cores (7, 8). 
Credit: Open Archaeology (2023). DOI: 10.1515/opar-2022-0289

Stone Age humans may have made extended maritime voyages on the Caspian Sea, according to a new study published in the journal Open Archaeology.

The research analyzed ornamental beads made from the disk-shaped shells of a species of cockle (Didacna sp.) found at the Kaylu rock shelter, a cave-like burial site near the eastern shoreline of the Caspian Sea.

Kaylu was used by Stone Age people over an extended period in the late Mesolithic and Neolithic periods. The transition between these periods is particularly significant in human cultural evolution as it parallels the transition between hunter-gathering cultures and herding and farming cultures, which occurred around 11,500 years ago in the region. Although Kaylu was excavated in the mid-twentieth century, its deposits were poorly described, and it wasn't comprehensively reassessed or directly dated until its rediscovery in 2018.

For this study, lead author Solange Rigaud of the CNRSand University of Bordeaux, France and colleagues used a wide range of tools and techniques to determine how the beads were made and used. Microscopic, morphometric, spectrometric and scanning electron microscopy (SEM) analyses showed a distinct stylistic change between the beads worn by the last hunter-gatherers and the first farmers.

Diversity of the personal ornaments documented at Jeitun, Turkmenistan, Early Neolithic. 
Credit: Open Archaeology (2023). DOI: 10.1515/opar-2022-0289

The analyses also enabled the researchers to compare the beads found at Kaylu with others from various sites across the region. Neolithic beads found in the northern, eastern and western Caspian Sea differed significantly enough from those found in the southern region to indicate that they followed a different route of cultural diffusion.

It is well-established that the southern Caspian Sea area played a major role in the spread of farming technologies and practices, with the movement of farmers and herders along a route through what is now northern Iran. Rigaud's results suggest that cultural traditions also spread around the northern coastline of the Caspian Sea, independently of the inland route.

However, another more exciting explanation is that Stone Age people engaged in maritime voyaging on the Caspian Sea. "Seafaring contacts between these communities may have granted the rapid circulation of specific bead-types—along with people, information, knowledge and symbols—from either side of the Caspian Sea by long maritime voyages," Rigaud said.


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Thursday, June 1, 2023

Revamping Energy Recovery: New Way To Efficiently Convert Waste Heat Into Electricity

By NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY (NIST) MAY 31, 2023 

Illustration of nanopillars used in a new design to efficiently convert heat energy into electricity. 
Credit: S. Kelley/NIST

A team from NIST and the University of Colorado Boulder have developed a novel device using gallium nitride nanopillars on silicon that significantly improves the conversion of heat into electricity. This could potentially recover large amounts of wasted heat energy, benefiting industries and power grids.

Researchers at the National Institute of Standards and Technology (NIST) have fabricated a novel device that could dramatically boost the conversion of heat into electricity. If perfected, the technology could help recoup some of the heat energy that is wasted in the U.S. at a rate of about $100 billion each year.

The new fabrication technique — developed by NIST researcher Kris Bertness and her collaborators — involves depositing hundreds of thousands of microscopic columns of gallium nitride atop a silicon wafer. Layers of silicon are then removed from the underside of the wafer until only a thin sheet of the material remains. The interaction between the pillars and the silicon sheet slows the transport of heat in the silicon, enabling more of the heat to convert to electric current. Bertness and her collaborators at the University of Colorado Boulder recently reported the findings in the journal Advanced Materials.

Once the fabrication method is perfected, the silicon sheets could be wrapped around steam or exhaust pipes to convert heat emissions into electricity that could power nearby devices or be delivered to a power grid. Another potential application would be cooling computer chips.

By growing nanopillars above a silicon membrane, NIST scientists and their colleagues have reduced heat conduction by 21% without reducing electrical conductivity, a result that could dramatically boost the conversion of heat energy into electrical energy. 
In solids, heat energy is carried by phonons, periodic vibrations of atoms in a crystal lattice. Certain vibrations of the phonons in the membrane resonate with those in the nanopillars, acting to slow the transfer of heat. Crucially, the nanopillars do not slow the movement of electrons, so that electrical conductivity remains high, creating a superior thermoelectric material. 
Credit: S. Kelley/NIST

The NIST-University of Colorado study is based on a curious phenomenon first discovered by German physicist Thomas Seebeck. In the early 1820s, Seebeck was studying two metal wires, each made of a different material, that were joined at both ends to form a loop. He observed that when the two junctions connecting the wires were kept at different temperatures, a nearby compass needle deflected. Other scientists soon realized that the deflection occurred because the temperature difference induced a voltage between the two regions, causing current to flow from the hotter region to the colder one. The current created a magnetic field that deflected the compass needle.

In theory, the so-called Seebeck effect could be an ideal way to recycle heat energy that would otherwise be lost. But there’s been a major obstacle. A material must conduct heat poorly in order to maintain a temperature difference between two regions yet conduct electricity extremely well to convert the heat to a substantial amount of electrical energy. For most substances, however, heat conductivity and electrical conductivity go hand in hand; a poor heat conductor makes for a poor electrical conductor and vice versa.

In studying the physics of thermoelectric conversion, theorist Mahmoud Hussein of the University of Colorado discovered that these properties could be decoupled in a thin membrane covered with nanopillars — standing columns of material no more than a few millionths of a meter in length, or about one-tenth the thickness of a human hair. His finding led to the collaboration with Bertness.

Using the nanopillars, Bertness, Hussein and their colleagues succeeded in uncoupling the heat conductivity from electrical conductivity in the silicon sheet — a first for any material and a milestone for enabling efficient conversion of heat to electrical energy. The researchers reduced the heat conductivity of the silicon sheet by 21% without lowering its electrical conductivity or changing the Seebeck effect.

In silicon and other solids, atoms are constrained by bonds and cannot move freely to transmit heat. As a consequence, the transport of heat energy takes the form of phonons — moving collective vibrations of the atoms. Both the gallium nitride nanopillars and the silicon sheet carry phonons, but those within the nanopillars are standing waves, pinned down by the walls of the tiny columns much the way a vibrating guitar string is held fixed at both ends.

The interaction between the phonons traveling in the silicon sheet and the vibrations in the nanopillars slow the traveling phonons, making it harder for heat to pass through the material. This reduces the thermal conductivity, thus increasing the temperature difference from one end to the other. Just as importantly, the phonon interaction accomplishes this feat while leaving the electrical conductivity of the silicon sheet unchanged.

The team is now working on structures fabricated entirely of silicon and with a better geometry for thermoelectric heat recovery. The researchers expect to demonstrate a heat-to-electricity conversion rate high enough to make their technique economically viable for industry.


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