It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Sunday, July 26, 2020
Archaeologists Discover Evidence of Ancient Temple Complexes at Navan Fort
Archaeologists conducting research at the Navan Fort in County Armagh, Northern Ireland have discovered evidence for consecutive temple complexes dating from the Iron Age.
The Navan Fort (Emain Macha in old Irish), is one of Ireland’s proposed royal sites and capital of the Ulaidh, that was documented during the medieval period as one of the five capitals of the five fifths that divided Ireland.
According to Irish mythology, the fort was also the seat of Chonchobhar mac Nessa, the king of Ulster in the Ulster Cycle and was described in the epic saga Táin Bó Cúailnge about the exploits of Cú Chulainn and Conal Cernach.
The fort lies at the heart of the ‘Navan complex’, which includes the Haughey’s Fort (an earlier hilltop enclosure), the King’s Stables (an artificial ritual pool) and Loughnashade (a natural lake that has yielded votive offerings) and consists of a large bank and ditch circular hilltop enclosure which also contains a small circular mound and a ring barrow.
The study by academics from Queen’s University Belfast, and the University of Aberdeen, in conjunction with the German Archaeological Institute, conducted a series of geophysical surveys which has revealed a vast ceremonial temple complex with further evidence of continuous activity through to the medieval period.
Dr Gleeson from Queen’s University Belfast said: “Excavation in the 1960s uncovered one of the most spectacular series of buildings of any region of prehistoric Europe, including a series of figure-of-8 buildings of the Early Iron Age and a 40m timber-ringed structure constructed c.95 BC. Upon the latter’s construction, it was immediately filled with stones and burnt to the ground in order to create a massive mound that now dominates the site.
Dr Gleeson added: “Our discoveries add significant additional data, hinting that the buildings uncovered in the 1960s were not domestic structures lived in by kings, but a series of massive temples, some of the largest and most complex ritual arena of any region of later prehistoric and pre-Roman Northern Europe.”
Nuclear sites still dangerous in 24,000 years, say space archaeologists
Some nuclear tests were conducted also in outer space and nuclear fuel was employed as propellant for rockets.
By ROSSELLA TERCATIN JULY 26, 2020 18:30 A mushroom cloud from the Trinity Nuclear Test. (photo credit: Wikimedia Commons) Advertisement
In July 1945, a test conducted in the deserts of New Mexico officially propelled humanity into the nuclear era. Only weeks after the Trinity Test, two atomic bombs were dropped on the Japanese cities of Hiroshima and Nagasaki. In the following decades, while no other nuclear device was detonated in an act of war, military tests and studies continued.
Seventy-five years later, space archaeologists are wondering how to warn humanity of the future that the sites where these experiments were carried out are still dangerous, Alice Gorman, associate professor at Flinders University in Adelaide, Australia, told The Jerusalem Post. “Teenagers nowadays do not understand how to work a dial telephone, a device that was incredibly common only one or two generations ago,” she said. “The type of plutonium used in the Trinity Test, plutonium-239, has a half-life of 24,000 years, meaning that after this time, only half of it will have decayed into a safe, non-radioactive element. How do we communicate to people living then that the site is dangerous?” Gorman said the issue presents two challenging elements: What materials can survive such a long time, and what form of language can be used to deliver the actual message? “As for the first difficulty, we know that stones and pottery last a very long time,” she said. “But the second point raises a big archaeological question related to symbolic communication. If we look at rock art from 20,000 years ago, we can see that there are pictures of animals, but we do not know what those pictures mean. Therefore, it is possible that our current symbols to mark radioactive sites, the yellow [and] black sign, will be interpreted as an invitation to explore the area, rather than to keep away from it.” The issue is especially important for archaeologists of the future because in some cases, while the danger would be very limited or not even relevant on the surface, the nuclear waste and its radiation are deeper in the ground, and conducting a dig would be especially risky. For example, such is the case of Maralinga, a remote area in southern Australia where the UK conducted several nuclear tests. Some nuclear tests were conducted in outer space, and nuclear fuel was employed as propellant for rockets. If the UN Outer Space Treaty of 1967 prohibited nuclear weapons in space, the issue of its weaponization remains very relevant. “Recently, Russia tested an anti-satellite weapon, reawakening the debate,” Gorman told the Post. She began to work in space archaeology following years of work focused on stone-tool analysis and the aboriginal use of bottle glass after European settlement. Space archaeology deals with the same issues of regular archaeology, understanding material culture, human behavior and the interaction with the surrounding environment, Gorman said. “However, we are looking at the post-Second World War period, when the very same rockets that had been developed as missiles started to send spacecraft into orbit,” she said. “We are interested in all of what is on earth, like rocket launch sites or tracking antennas and reception development, as well as town or residential areas where people who worked on these projects live, but also satellites, space junk and all the places on other planets where humans have sent spacecrafts.” “We are asking the same questions other archaeologists are, but we have the limitations that we cannot visit many of the sites in person, and instead, we have to rely on records or images,” she added. Gorman was drawn to space archaeology by the idea of exploring space junk, those many objects that cannot even be seen in the sky circling the Earth. Currently, she is working on the archaeology of the International Space Station. The recent attempt by Israel to land a robotic unit on the moon with the Beresheet mission represents a very interesting development for space archaeologists, Gorman said. “For many decades, the only material cultures present on the moon were the American and the Soviet one,” she said. “As new countries have started to reach the moon, this has changed, bringing more diversity to the field.”
Christian, Muslim symbols found in 7th century shipwreck in Israel
Moreover, the ship also offers important insights in terms of ship construction techniques.
Students Maayan Cohen and Michelle Creisher examine the pottery near the bulkhead at Ma‘agan Mikhael B shipwreck. (photo credit: A. YURMAN/LEON RECANATI INSTITUTE FOR MARITIME STUDIES OF THE UNIVERSITY OF HAIFA.)
About 1,300 years ago, a 25-meter-long ship sank just a few dozen meters from the coast of Israel. Most likely, nobody perished in the incident. But its plentiful cargo included 103 amphorae filled with all forms of agricultural products, numerous daily objects used by the crew and many other unique features, such as several Greek and Arabic inscriptions. They were swallowed by the sea and the sand, which preserved their secrets for centuries.
First spotted by two members of nearby Kibbutz Ma’agan Michael, about 35 km. south of Haifa, the site was again covered by sand and rediscovered in 2015. The shipwreck has been excavated by the University of Haifa’s Leon Recanati Institute for Maritime Studies since 2016. It has offered archaeologists unique insights into the life of the region at the time of the transition between Byzantine and Islamic rule, trade routes and ship construction. Moreover, the site presents the largest maritime cargo collection of Byzantine and early Islamic pottery discovered in Israel, not devoid of mystery, since two of the six types of amphorae had never before been uncovered. The first results of the excavations were examined in two academic papers recently published in the journals Levant and Near Eastern Archaeology. “We have not been able to determine with certainty what caused the ship to wreck, but we think it was probably a navigational mistake,” University of Haifa archaeologist Deborah Cvikel, an author of both papers, told The Jerusalem Post. “We are talking about an unusually large vessel, which was carefully built and is beautifully conserved.” Based on the findings, the researchers believe the ship must have made stops in Cyprus, Egypt and possibly a port along the coast of Israel before sinking, she said, adding: “It was definitely traveling around the Levant.” The size and richness of the cargo seem to contradict the notion, currently popular among scholars, that during the transition between Byzantine and Islamic rule between the seventh and eighth centuries, commerce in the Eastern Mediterranean was limited. Inscriptions found by the archaeologists have provided a glimpse of the fascinating complexity of the period, with both Greek and Arabic letters, as well as Christian and Muslim religious symbols, making their way to the ship – whether carved in the wood of the vessel or on the amphorae. “We do not know whether the crew was Christian or Muslim, but we found traces of both religions,” Cvikel said. The symbols include the name of Allah written in Arabic, as well as several crosses. Among the products found in the pottery were olives, dates, figs, fish bones, pine nuts, grapes and raisins. Many animal bones were found on the ship, perhaps do to eating practices or because they were kept by the crew as pets. “We have not found any human bone, but we assume that because the ship sank so close to the coast, nobody died in the wreckage,” Cvikel said. What also makes the site unique is that among the six types of amphorae identified by the archaeologists, two typologies had never emerged anywhere else. Most of the other vessels appeared to have been made in Egypt. Moreover, the ship also offers important insights in terms of ship construction techniques. “Ships were built using a method called ‘shell-first’ construction, which was based on strakes, giving the hull its shape and integrity,” Cvikel told the Post. “The main characteristic of this method is the use of mortise-and-tenon joints to connect hull planks. During the fifth to sixth centuries CE, ‘skeleton-first’ construction, in which strakes were fastened to the preconstructed keel and frames, was used. “This process of ‘transition in ship construction’ has been one of the main topics in the history of shipbuilding for about 70 years, and some issues have remained unanswered. Therefore, each shipwreck of this period holds a vast amount of information that can shed further light onto the process.” The excavation of the site, which is carried out with the involvement of several master’s and doctoral students, is ongoing, even though this summer the coronavirus emergency has prevented the archaeologist from going back to it. “We still need to uncover the rear part of the ship, where presumably the captain lived,” Cvikel said. “We also need to carry out more analysis on many of the findings, including the amphorae, their content, the everyday objects, such as the cookware, and the animal bones.”
An origin story for a family of oddball meteorites
Most meteorites that have landed on Earth are fragments of planetesimals, the very earliest protoplanetary bodies in the solar system. Scientists have thought that these primordial bodies either completely melted early in their history or remained as piles of unmelted rubble.
But a family of meteorites has befuddled researchers since its discovery in the 1960s. The diverse fragments, found all over the world, seem to have broken off from the same primordial body, and yet the makeup of these meteorites indicates that their parent must have been a puzzling chimera that was both melted and unmelted. Now researchers at MIT and elsewhere have determined that the parent body of these rare meteorites was indeed a multilayered, differentiated object that likely had a liquid metallic core. This core was substantial enough to generate a magnetic field that may have been as strong as Earth's magnetic field is today.
Their results, published in the journal Science Advances, suggest that the diversity of the earliest objects in the solar system may have been more complex than scientists had assumed.
"This is one example of a planetesimal that must have had melted and unmelted layers. It encourages searches for more evidence of composite planetary structures," says lead author Clara Maurel, a graduate student in MIT's Department of Earth, Atmospheric, and Planetary Sciences (EAPS). "Understanding the full spectrum of structures, from nonmelted to fully melted, is key to deciphering how planetesimals formed in the early solar system."
Maurel's co-authors include EAPS professor Benjamin Weiss, along with collaborators at Oxford University, Cambridge University, the University of Chicago, Lawrence Berkeley National Laboratory, and the Southwest Research Institute.
Oddball irons
The solar system formed around 4.5 billion years ago as a swirl of super-hot gas and dust. As this disk gradually cooled, bits of matter collided and merged to form progressively larger bodies, such as planetesimals.
The majority of meteorites that have fallen to Earth have compositions that suggest they came from such early planetesimals that were either of two types: melted, and unmelted. Both types of objects, scientists believe, would have formed relatively quickly, in less than a few million years, early in the solar system's evolution.
If a planetesimal formed in the first 1.5 million years of the solar system, short-lived radiogenic elements could have melted the body entirely due to the heat released by their decay. Unmelted planetesimals could have formed later, when their material had lower quantities of radiogenic elements, insufficient for melting.
There has been little evidence in the meteorite record of intermediate objects with both melted and unmelted compositions, except for a rare family of meteorites called IIE irons.
"These IIE irons are oddball meteorites," Weiss says. "They show both evidence of being from primordial objects that never melted, and also evidence for coming from a body that's completely or at least substantially melted. We haven't known where to put them, and that's what made us zero in on them."
Magnetic pockets
Scientists have previously found that both melted and unmelted IIE meteorites originated from the same ancient planetesimal, which likely had a solid crust overlying a liquid mantle, like Earth. Maurel and her colleagues wondered whether the planetesimal also may have harbored a metallic, melted core.
"Did this object melt enough that material sank to the center and formed a metallic core like that of the Earth?" Maurel says. "That was the missing piece to the story of these meteorites."
The team reasoned that if the planetesimal did host a metallic core, it could very well have generated a magnetic field, similar to the way Earth's churning liquid core produces a magnetic field. Such an ancient field could have caused minerals in the planetesimal to point in the direction of the field, like a needle in a compass. Certain minerals could have kept this alignment over billions of years.
Maurel and her colleagues wondered whether they might find such minerals in samples of IIE meteorites that had crashed to Earth. They obtained two meteorites, which they analyzed for a type of iron-nickel mineral known for its exceptional magnetism-recording properties.
The team analyzed the samples using the Lawrence Berkeley National Laboratory'sAdvanced Light Source, which produces X-rays that interact with mineral grains at the nanometer scale, in a way that can reveal the minerals' magnetic direction.
Sure enough, the electrons within a number of grains were aligned in a similar direction—evidence that the parent body generated a magnetic field, possibly up to several tens of microtesla, which is about the strength of Earth's magnetic field. After ruling out less plausible sources, the team concluded that the magnetic field was most likely produced by a liquid metallic core. To generate such a field, they estimate the core must have been at least several tens of kilometers wide.
Such complex planetesimals with mixed composition (both melted, in the form of a liquid core and mantle, and unmelted in the form of a solid crust), Maurel says, would likely have taken over several million years to form—a formation period that is longer than what scientists had assumed until recently.
But where within the parent body did the meteorites come from? If the magnetic field was generated by the parent body's core, this would mean that the fragments that ultimately fell to Earth could not have come from the core itself. That's because a liquid core only generates a magnetic field while still churning and hot. Any minerals that would have recorded the ancient field must have done so outside the core, before the core itself completely cooled.
Working with collaborators at the University of Chicago, the team ran high-velocity simulations of various formation scenarios for these meteorites. They showed that it was possible for a body with a liquid core to collide with another object, and for that impact to dislodge material from the core. That material would then migrate to pockets close to the surface where the meteorites originated.
"As the body cools, the meteorites in these pockets will imprint this magnetic field in their minerals. At some point, the magnetic field will decay, but the imprint will remain," Maurel says. "Later on, this body is going to undergo a lot of other collisions until the ultimate collisions that will place these meteorites on Earth's trajectory."
Was such a complex planetesimal an outlier in the early solar system, or one of many such differentiated objects? The answer, Weiss says, may lie in the asteroid belt, a region populated with primordial remnants.
"Most bodies in the asteroid belt appear unmelted on their surface," Weiss says. "If we're eventually able to see inside asteroids, we might test this idea. Maybe some asteroids are melted inside, and bodies like this planetesimal are actually common." Ancient micrometeoroids carried specks of stardust, water to asteroid 4 Vesta More information: Meteorite evidence for partial differentiation and protracted accretion of planetesimals, Science Advances (2020). Journal information: Science Advances
Well-preserved mammoth skeleton found in Siberian lake
Russian scientists are working to retrieve the well-preserved skeleton of a woolly mammoth, which has some ligaments still attached to it, from a lake in northern Siberia. Fragments of the skeleton were found by local reindeer herders in the shallows of Pechevalavato Lake on the Yamalo-Nenets region a few days ago. They found part of the animal’s skull, the lower jaw, several ribs, and a foot fragment with sinews still intact. Woolly mammoths are thought to have died out around 10,000 years ago, although scientists think small groups of them may have lived on longer in Alaska and on Russia’s Wrangel Island off the Siberian coast. Russian television stations on Friday showed scientists looking for fragments of the skeleton in the lakeside silt. Scientists have retrieved more bones and also located more massive fragments protruding from the silt. They said it would take significant time and special equipment to recover the rest of the skeleton — if it had all survived in position. Read the rest of this article...
Air pollution affects brain development – but when does the damage start?
The emergency rooms in Barcelona were collapsing under the pressure. Hundreds of patients were arriving in desperate need as they struggled to breathe, while intensive care units struggled to cope with the sudden influx of respiratory problems. Epidemiologists scrambled to trace the source of the outbreak.
This epidemic in the 1980s might bear some striking similarities to the coronavirus pandemic, but there was no infection to blame. The city was suffering from outbreaks of asthma.
Between 1981 and 1989, 26 outbreaks of asthma were reported in the Spanish city with many cases centred around the harbour. Local scientists eventually discovered that the cause was soybean dust released into the air when the cargo was unloaded.
The solution was simple enough – filters to cover the soybeans silos – however, the episode left a remarkable legacy in the scientific community in Barcelona, which could help us to identify a significant risk to brain development in children.
The asthma epidemics were initially thought to be due to air pollution from burning fossil fuels, so the researchers created a register to map its potential impact. This became the basis for the local researchers to continue to monitor the effects of dirty air over the decades since.
Although the immediate effect of air pollution on asthma was much weaker than the soybean dust, it was affecting the population on a daily basis. Over time, air pollution appeared to be responsible for more emergency room admissions for asthma than the acute soybean-related epidemics.
Air pollution
Professor Jordi Sunyer from ISGlobal, the Barcelona Institute for Global Health, was one of the researchers who discovered the link to soybeans and investigates the effects of air pollution.
‘In the 80s, home combustion of coal was a major problem, and the levels of sulphur oxide were very high. This was controlled but now, especially in Europe, there is a dramatic increase in traffic and diesel combustion,’ he said.
As well as changes in the type of pollution, he says that we have come to understand better the extent of damage caused by air pollution, beyond the lungs.
‘In the 90s, it appeared that the cardiovascular system was a major target of air pollution. Then in 2008, there were studies in animals that showed an effect on the brain,’ he said. ‘This was because the size of the particles of pollution was so small that they could go into the brain and cause neuroinflammation.’
In 2015, Prof. Sunyer and his colleagues published research showing that higher pollution levels were linked to a 5% decrease on tests of working memory in children aged 7 to 10.
‘This is the same amount of change that was found several years ago between children with high levels of lead in the blood and children with lower levels in the blood,’ said Prof. Sunyer.
When the lead pollution from petrol was found to be causing widespread harm, unleaded petrol was introduced from the 1970s. At an individual level, a 5% decrease on a test would not be enough to make an obvious impact, but on a population level it could have a significant economic cost says Prof. Sunyer.
He adds that 90% of brain development happens by the age of four, so he is now following up on his previous study to understand the effects of air pollution at the earliest stages of life.
He is leading the AIR-NB study to monitor the exposure to air pollution before the child is even born. The research team is recruiting 1,200 pregnant women in Barcelona to the study and measuring the pollution levels in their homes.
Taking into account other possible factors, such as physical activity, noise pollution and the mother’s stress hormones, they will try to identify differences between the children as they develop. The researchers will be imaging their brains at the third trimester of pregnancy and from one month after birth using MRI scans.
Autism
Another concern is that air pollution can raise the risk of developing autism spectrum disorder. Several studies in the US suggested that there is a link to air pollution, but the results from a big European project found no connection. However, this research brought together results from different studies that used different methods, which may have affected the results.
Dr Juana Maria Delgado-Saborit, a visiting researcher at ISGlobal, hopes to help investigate this issue by using data on 18,000 children in the UK. These children are all part of the Millennium cohort study and have been regularly monitored and tested over the past two decades.
‘I thought that maybe with that big cohort there might be the chance to see if there is a real problem in UK and Europe, or if the Americans are seeing a difference because of the composition of the pollution,’ she said.
For a project called COGNAC, Dr Delgado-Saborit is using health information collected on the children up to the age of 14 to look for diagnoses of autism spectrum disorder or traits of the condition. By overlaying this information with maps of pollution during pregnancy and in their early years, she hopes to identify any potential links.
The analysis of the data is ongoing, but her early results suggest that there is a connection with levels of ozone in the air. Ozone is an irritant that is formed by a reaction involving nitrogen oxides and hydrocarbons, common pollutants from road traffic.
Change
Both Dr Delgado-Saborit and Prof. Sunyer draw parallels to the change in perspective of the damage caused by air pollution following the thousands of deaths from the Great Smog of London in 1952.
‘From the industrial revolution, we knew that we were making our environment dirty, but we didn’t have the evidence (of harm). When we started measuring the changes, we started to realise that something was happening, especially when we had the episode of London smog. That kick-started (the realisation) that the air is having an impact on our health,’ said Dr Delgado-Saborit.
‘Then there was the Clean Air Acts and the air was cleaned. In the 80s it was thought that the levels (of pollution) were safe for health,’ said Prof. Sunyer.
Just like the 1950s, there is widespread understanding today that our dirty air is not safe, but we still do not know how great an impact it has on our lives. While there is acceptance that children at school should not be exposed to high levels of air pollution, Prof. Sunyer says, the results of their research could have far-reaching consequences:
‘If we found pregnancy and early life is a more vulnerable period, I think this would force society to find new ways to live in cities that also protect the health of children.’
However, compared to putting a lid on soybean dust, this may prove to be a big challenge.
The research in this article was funded by the EU. If you liked this article, please consider sharing it on social media.
As the trees, shrubs, grass and peat are engulfed by these fires, huge quantities of smoke, soot and other pollutants are released into the air. With large fires, the smoke can rise many kilometres into the stratosphere and spread across entire regions, causing air pollution in areas far away from where the flames actually were.
‘In the eastern Mediterranean we get smoke that blows down from forest fires in Russia and when it happens there is just hazy smoke everywhere,’ said Professor Athanasios Nenes, an atmospheric chemist at the Institute of Chemical Engineering Sciences in Patras, Greece. ‘It can be quite dramatic. They are affecting air quality over entire regions or parts of continents.’
Prof. Nenes is principal investigator of the PyroTRACH project, which is attempting to find out how emissions from wildfires – along with other types of biomass burning, such as domestic wood fires – change in the atmosphere and the impact this has on human health and climate.
The team is taking regular air samples at three locations in Greece – Crete, Athens and Patras. These are being combined with samples provided by collaborators around the world including in the US, the Arctic, India, Europe, Vietnam and in the air above the south Atlantic Ocean.
‘When you look at these samples, you can always find a lot of particles in the air, but you can’t say for sure whether it has come from biomass burning,’ said Prof. Nenes. ‘The idea behind PyroTRACH is to see if we can identify specific signatures of fires and, in addition, track what happens to the smoke as it ages in the atmosphere.’
Air pollution picked up by samplers, such as the one in Patras, Greece, could have come from fires thousands of kilometres away. Image credit – Spiro Jorga
Age
To do this, the researchers are using a special environmental chamber in the laboratory that replicates the conditions found in the atmosphere. They then generate fresh smoke samples by burning different types of plant material, which are then allowed to “age” in the chamber.
Over time they are able to see how the chemistry of the particles in the smoke changes when exposed to the atmosphere and daily patterns of sunlight and darkness. Portable chambers also allow them to age smoke directly produced from real fires in the outside environment.
‘We are trying to understand the lifetime of smoke in the atmosphere and how it chemically evolves,’ said Prof. Nenes. ‘We want to characterise the impacts it will have on human health and the climate. Does it become more toxic (with age), or have a greater (warming) effect on the climate (than currently thought), or supply more nutrients to ecosystems when it falls back to the ground?’
One of the key findings the team has made since the five-year project began in 2017 is that particles released from burning vegetation in forest fires become more toxic over time.
Smoke from forest fires can linger in the atmosphere for a couple of weeks as it spreads. While in the air the smoke particles chemically react with trace radicals – molecules with unpaired electrons – to undergo a process known as oxidation. This converts the compounds in the smoke particles into highly reactive compounds. When they are breathed in, these reactive compounds – known as free radicals – can damage cells and tissues in the body.
‘We know that breathing in smoke when you are close to a fire is not good, but we have seen that over time it gets worse – up to four times more toxic a day down the road,’ said Prof. Nenes, referring to some of their experiment results. These results showed smoke samples taken from the air more than five hours after they were released from a fire were twice as toxic than when they were first released and as they aged further in the laboratory the toxicity increased to four times the original levels.
‘This means that even if you are far away from a fire, if the smoke is being blown towards you, it can have a significant impact on health,’ he said. ‘People might not even be aware they are breathing in the fumes from a faraway forest fire, but it will be affecting their health.’
‘People might not even be aware they are breathing in the fumes from a faraway forest fire, but it will be affecting their health.’
Professor Athanasios Nenes, Institute of Chemical Engineering Sciences, Greece
Health
While the exact health effects of breathing in this smoke are still to be fully understood, Prof. Nenes and his team will feed their results into another project called REMEDIA. It is looking at how air pollution affects the lungs as part of the Human Exposome Network, which focuses on what environmental exposures do to human health.
But reactive compounds from wildfire smoke are thought to have a number of short and long-term health effects.
‘They can make people more prone to infections, can lead to breathing difficulties and leave some people more prone to heart attacks,’ said Prof. Nenes. ‘At the same time the smoke particles also contain carcinogens – polyaromatic hydrocarbons – which also oxidise and become more carcinogenic, increasing the risk of cancers.’
This increase in toxicity is a particular concern as smoke from large wildfires is known to travel across whole continents and even oceans. Smoke billowing from forest fires in Alberta, Canada, for example, was tracked as spreading down the east coast of the US, across the Atlantic and into Europe in 2019. Similarly, smoke from the recent devastating fires in Australia engulfed South America and pollution from wildfires in Siberia have spread to western Canada and the US.
‘Wildfire smoke can circulate the globe,’ said Dr Mike Flannigan, director of the Canadian Partnership for Wildland Fire Science at the University of Alberta. ‘Smoke from intense fire can be injected into the upper atmosphere where strong winds – typically west winds – can carry it rapidly around the world.’
This means that large wildfires can have dramatic impacts on the air quality and visibility in cities far away from the source of the smoke, which can then make urban air pollution worse, increasing the risk of health problems and deaths among those living there.
Samples of air in downtown Athens, Greece, along with others from around the world, are being analysed to see if signature particles from wildfires can be identified. Image credit – Irini Tsiodra
Smoke
In Europe there are on average 65,000 wildfires every year, but the region is also engulfed by seasonal clouds of smoke from blazes further afield too.
Through the colder winter months domestic wood burning contributes a significant fraction of the smoke in the atmosphere, particularly in urban areas, according to Prof. Nenes.
More work is needed to understand the many sources of pollution in the air. Unravelling these sources is the goal of the Aeromet project. It is developing new ways of better analysing the aerosols and particles that pollute the air, particularly in urban areas across Europe. Currently it is difficult to distinguish which come from natural sources – such as dust blown into the air and salt lifted off the oceans by the wind – and those that come from fires, vehicles, industry and other human activities.
Improving the accuracy of how these are measured and identified could not only help authorities monitor air pollution better, but also ‘potentially help to identify critical single sources of particles and to propose appropriate counter-measures to improve air quality’ based upon the findings, says Dr Burkhard Beckhoff, coordinator of the Aeromet project and a researcher at Germany’s Physikalisch-Technische Bundesanstalt in Berlin.
Prof. Nenes hopes that characterising the pollution from wildfires and domestic woodburning could help to improve climate change models as some of the soot released by fires – known as brown carbon – plays a considerable role in absorbing heat from the sun, and makes global warming worse.
‘The smaller brown carbon molecules tend to bleach quite quickly but larger ones are more resilient, creating a low but persistent heating effect,’ he said.
Knowing how much of this brown carbon is produced in wildfires and domestic woodburning would allow climate scientists to make better climate predictions.
With climate models already predicting that wildfires are likely to become more common and intense as global temperatures increase, and domestic wood burning on the rise, the smoke they produce could pose an even greater risk to human health and the environment, says Prof. Nenes.
‘I grew up being able to see the effect fires have on our air here in Greece,’ he said. ‘It is alarming to think about what we are doing to ourselves and the environment. But hopefully as we understand more about this, we can contribute to policies that should be developed to help mitigate the impact of these fires.’
The research in this article was funded by the EU. If you liked this article, please consider sharing it on social media.
OptiFuel Systems (“OptiFuel”), a system integrator of Cummins and BAE Systems hybrid power products for decarbonizing the rail, marine, and microgrid power market, is in the process of finalizing a $2.6 million U.S. Department of Energy (DOE) grant to demonstrate a pre-production Renewable Natural Gas (RNG) hybrid 4,300 hp line-haul locomotive. The program will demonstrate that a suite of commercially available, EPA rail-certified engines present a near-term, low risk solution to create an affordable RNG hybrid line-haul locomotive with near zero emissions while simultaneously improving fuel cost by 50%. This new program, partially funded with the DOE grant, will allow pre-production testing at AAR’s Transportation Technology Center, Inc. (TTCI) and will operate in-service with a regional railroad to validate that OptiFuel’s low-risk, affordable technology can also be applied in the higher horsepower freight and passenger locomotive market.
This program is integral to OptiFuel’s 5-year plan to disrupt and decarbonize the rail market with a full line of zero and near-zero NOx, PM and CO2 emissions freight and passenger locomotives. In several weeks, OptiFuel will be announcing that it will start taking orders, in 49 of the U.S. states, for a new line of affordable 800 hp to 3,200 hp, 100% natural gas freight and transit locomotives. All will have zero NOx/PM emissions with carbon-neutral emissions by consuming an RNG/CNG mixture. OptiFuel has already developed and tested a high volume CNG/RNG refueling system at the Indiana Harbor Belt CNG locomotive program, utilizing low-cost CNG. In the next 2 years, OptiFuel will be announcing additional refueling products, including an affordable 12,000 DGE (Diesel Gallon Equivalent) CNG/RNG tender; and a 9,000 CNG/RNG DGE, 1,600 hp zero emission, powered tender.
The Rail Sector is the only transportation modality without significant emissions related development that is feasible in the near-term to eliminate ozone, smog and GHG emissions. In comparison, the composite US freight line-haul fleet, which consumes 90% of the fuel in the rail industry, emits 8 g/bhp-hr of NOx while new CNG Class 8 trucks emit 0.02 g/bhp-hr of NOx, a reduction of 400 times. Even if locomotives can carry 4 times amount of tonnage per horsepower as a new CNG Class 8 trucks, it still has emissions 100 [sic] higher. Beside the U.S. locomotive fleet average NOx emissions of 8 g/bhp-hr, the U.S. rail fleet’s average fine Particulate Matter (PM) emissions is 0.22 g/bhp-hr. In comparison, OptiFuel’s 4,300 RNG hybrid line-haul locomotive is expected to emit 0.04 g/bhp-hr of NOx, a reduction of 200 times, and emit 0.00 g/bhp-hr of PM. Using RNG as the fuel, OptiFuel’s locomotive will dramatically lower greenhouse gas (GHG) emissions resulting in a neutral or negative carbon footprint, in addition to far exceeding California’s Tier 5 locomotive petition standards to U.S. EPA.
As of September 2016, there were more than 1,000 railyards in the U.S. located in densely populated, urban areas classified as particulate matter and ozone EPA defined “nonattainment” areas. More than 122 million people (nearly 40% of the U.S. population) living in these nonattainment areas are having more acute and chronic adverse health outcomes, including exacerbation of respiratory and cardiovascular disease. In these U.S. railyards, there are more than 28,000 technologically obsolete, diesel powered locomotives operating which produce Pre-Tier 0 (non-regulated, pre-1973), Tier 0 or Tier 1 emissions. These pollutants create very high levels of ozone, air toxins, greenhouse gases, fine particulate matter, and other diesel exhaust compounds classified as carcinogenic to humans.
In 2018, Class I, II, and III railroads purchased 4.7 billion gallons of diesel fuel for the 39,000 locomotives used for freight operations in the US. Freight railroads emitted more than 1.6 million tons of NOx, 43,000 tons of PM, and 38 million metric tons of CO2, much of which occurs in Environmental Justice communities. OptiFuel’s EPA rail certified technology with a CNG/RNG fuel mixture would limit railroad emission throughout the U.S. to 8,600 tons of NOx, zero tons of PM, and zero metric tons of CO2.
This demonstration will include a comprehensive natural gas hybrid propulsion package featuring four 100% natural gas engines– the OptiFuel KOFSG11.9400 (“OFS12”) and a single Cummins Tier 4, EPA rail certified, diesel-powered QSK60 in a hybrid configuration. Our design also includes a 100% battery-electric mode for limited yard operations. OptiFuel’s OFS12 engine is EPA rail certified with emissions of 0.00 g/bhp-hr for both NOx and PM, and is capable of operating on either CNG, RNG, LNG, or a CNG-RNG blend. The OFS12 engine, which is identical to the Cummins ISX12N for on-road applications, is the cleanest rail engine currently certified by EPA.
The pre-production locomotive will consume 83% natural gas along with 20% improved efficiency versus Tier 4 diesel line-haul freight locomotives. OptiFuel will utilize one of its proprietary, Federal Railway Administration approved onboard CNG/RNG storage system holding 1,500 DGE to complete the locomotive design.
The production locomotive will be market competitive in pricing and will have an industry-leading 5-year warranty on all engines along with comprehensive maintenance coverage. The propulsion system design is compact enough to fit on virtually any legacy EMD or GE line-haul locomotive with no structural modifications to the operator cab or frame. OptiFuel design will allow the railroads to repower existing Tier 3 and Tier 4 line-haul locomotives at half the cost of fully replacing older Pre-Tier 0 to Tier 2 locomotives. In production, OptiFuel will provide its proven locomotive CNG fueling station solution and expect the CNG to cost between 0.70 to $1.35 per DGE, depending on capitalization and implementation strategies of the locomotive operator. This is well below the 10-year average cost of $2.45 that the Class 1 railroads have paid for diesel.
“We developed and certified these technologies for rail, because we believe there is a need for line-haul locomotives that deliver value and cleaner, more economical solutions simultaneously to railroads, railroad customers, and urban and Environmental Justice communities,” said Scott Myers, President of OptiFuel. “With the transportation and non-transportation mobile sector emitting 37% of all GHG emissions in the United States, it is critical to repower or replace all mobile assets to operate on carbon-neutral or carbon-negative renewable fuels such as RNG, Green Methane, Green Hydrogen or other biofuels, eliminating carbon-intensive gasoline or diesel fuels in the U.S. in 15 years.”
New York, New Haven & Hartford FL9 electric/diesel electric “dual-mode” locomotive-hauled train
Image above: Roger Puta
Published by Alan Kandel
Passion for purple revives ancient dye in Tunisia by Kaouther Larbi
After years of trial and error - and after getting used to the foul stench - Mohamed Ghassen Nouira has cracked how to make the prized purple dye used for royal and imperial robes in ancient times
A Tunisian man has pieced together bits of a local secret linked to ancient emperors: how to make a prized purple dye using the guts of a sea snail.
"At the beginning, I didn't know where to start," said Mohamed Ghassen Nouira, who heads a consulting firm.
"I would crush the whole shell and try to understand how this small marine animal released such a precious colour."
Now, after years of trial and error—and after getting used to the foul stench—he uses a hammer and small stone mortar to carefully break open the spiny murex shells.
What happens next is part of a secret guarded so closely that it disappeared hundreds of years ago.
A symbol of power and prestige, the celebrated purple colour was traditionally used for royal and imperial robes.
Production of the dye was among the main sources of wealth for the ancient Phoenicians, and then for the Carthaginian and Roman empires, said Ali Drine, who heads the research division of Tunisia's National Heritage Institute.
The industry was "under the control of the emperors because it brought a lot of money to the imperial coffers", he said.
In August 2007 on a Tunisian beach, Nouira found a shell releasing a purplish red colour, reminding him of something he'd learnt in history class at school.
He bought more shells from local fishermen and set out experimenting in an old outside kitchen at his father's house that he still uses as a workshop.
To obtain one gramme of pure purple dye, Nouira said he had to shell 100 kilogrammes of murex
Secret know-how
"Experts in dyeing, archaeology and history, as well as chemistry, helped and encouraged me, but nobody knew the technique," Nouira said.
No historical documents clearly detail the production methods for the purple pigment, Drine said.
"Maybe because the artisans did not want to divulge the secrets of their know-how, or they were afraid to because the production of purple was directly associated with the emperors, who tolerated no rivalry," he said.
The only clues for unearthing the techniques lie in archaeological sites and artefacts in the Mediterranean, particularly in Tyre in southern Lebanon, and Meninx, on the coast of Tunisia's Djerba island.
Phoenicians from Tyre set down the foundations of what would become the Carthaginian empire on the Tunisian coasts.
Also known as Tyrian purple, the pigment is still highly valued today and is produced by just a handful of people around the world.
They include a German painter and a Japanese enthusiast, each with their own secret techniques.
No historical documents clearly detail the production methods for the purple pigment, Drine said
Among the buyers are collectors, artists and researchers.
The dye can cost $2,800 per gramme from some European traders, and prices can reach up to $4,000, Nouira said.
He said he had produced a total of several dozen grammes of the pure purple dye, which he sells internationally for more modest prices.
'Not a cooking recipe'
Nouira said that when he sought help from other dye-makers, one told him bluntly, "'it's not a cooking recipe to be passed around.'"
"That made me even more determined. It drove me to read more and redouble my efforts."
In a wooden box where he keeps his stock, ranging from indigo blue to violet, Nouira carefully guards a dye sample from 2009—a "dear memento of my first success".
"I improved my methods until I found the right technique and mastered it from 2013-2014," he said.
A symbol of power and prestige, the celebrated purple colour was traditionally used for royal and imperial robes
To obtain one gramme of pure purple dye, Nouira said he had to shell 100 kilogrammes of murex, a task that takes him two weekends.
He washes the marine snails and sorts them by species and size, then carefully breaks the upper part of the shells to extract the gland that, after oxidisation, produces the purple colour.
Nouira said his greatest wish was to see his work exhibited in Tunisian museums.
"Purple has great tourist potential," he added, expressing a desire to one day also conduct workshops.
But he lamented what he said was the authorities' lack of interest in the craft.
In the meantime, he too is keeping his trade secrets close, and said he hoped to pass them on to his children.
"I'm very satisfied, and I'm also proud to have revived something related to our Carthaginian ancestors."
Police declared a riot at Seattle anti-racism protest and arrested at least 45 people Carmen Reinicke
Police face off with demonstrators during protests in Seattle on July 25, 2020 in Seattle, Washington. Police and demonstrators clash as protests continue in the city following reports that federal agents may have been sent to the city. David Ryder/ Getty Images
At least 45 people were arrested at an anti-racism march on Saturday, Seattle Police said on Twitter.
Police declared the march a riot after protesters set fire to a construction site and continued to a local precinct, where at least one person breached its fence line, and a device exploded.
The crowd also threw bricks, rocks, mortars, and other explosives at officers, according to a police report.
Twenty-one officers were left with mostly minor injuries following the incident.
At least 45 people were arrested at an anti-racism march in Seattle on Saturday that police declared a riot. In addition, 21 officers were also injured, the Seattle police said on Twitter.
Police clashed with protesters Saturday in what was one of the largest Black Lives Matter protests Seattle has seen in weeks, Reuters reported. The march was also in support of ongoing anti-racism protests, including those in Portland, Oregon, which have seen violent clashes with authorities, according to the BBC.
Police used "less-lethal equipment including OC spray, blast balls, and 40 mm sponge rounds" in an attempt to disperse large crowds after some protesters set fire to a construction site at the King County Youth Service Center and courthouse, according to a police statement.
The group continued to the East Precinct, where at least one person breached the precinct's fence line, and moments later a device exploded, leaving an 8-inch hole in the side of the building, according to a police report. The crowd also threw bricks, rocks, mortars, and other explosives at officers, according to the report.
Police arrested at least 45 people for assaults on officers, failure to disperse, and obstruction. Most of the 21 officers that sustained injuries at the day's events were able to return to duty, while one was treated at a hospital for a knee injury, the police said on Twitter.
On Thursday, the Trump administration sent a team of tactical border officers to Seattle, expanding its pledge to protect federal property that also sent officers to Portland, the New York Times reported.
Seattle Police Chief Carmen Best on Saturday called for peace and told reporters she had not seen any of the dispatched officers, the Associated Press reported.
