Tag Archives: wood

Off-cuts of wood show Vikings were settled in America one thousand years ago

Several wooden items discovered at an archaeological site in Newfoundland, Canada, paint an exciting picture: Vikings were on these shores in AD 1021, one thousand years ago. This would be the earliest known human crossing of the Atlantic in history, preceding Columbus’ discovery of the Americas by over 450 years.

Aerial image of a reconstructed Viking-Age building adjacent to the L’Anse aux Meadows site. Image credits Glenn Nagel Photography.

It isn’t exactly news that the Vikings reached the Americas before European explorers officially ‘discovered’ it. To the best of our knowledge, these Scandinavian explorers settled at a site known as L’Anse aux Meadows in what is today the Newfoundland peninsula. We know this was happening as early as the first millennium BC, but we didn’t have a precise date as to when.

New research, however, comes to give us a reliable estimation of when the first Europeans reached and settled these shores.

One man’s trash…

“The artefacts are not ‘display pieces’ or ‘works of art’ in any sense. They are actually just off-cuts of wood. Pieces of wood that were discarded by the Vikings,” explained Prof. Dr. Michael Dee, Associate Professor of Isotope Chronology at the University of Groningen and corresponding author of the paper, for ZME Science in an email. “The wood ended up in a nearby bog and the conditions in that bog were very good for the preservation of organic material. That is how they have survived until today.”

These pieces of wood were identified as having belonged to Vikings based on their location within the settlement, and by evidence on their surface of being processed using metal tools. Indigenous people living in America at the time did not have knowledge of metalwork, making this a very reliable indication of the artifacts’ origins.

The authors analyzed these pieces of wood found at the L’Anse aux Meadows site using carbon-dating (or ‘radiocarbon dating’) techniques. While this type of analysis cannot reveal when the timber was processed, it can tell us when the original trees were first cut down. While organisms such as plants live, they take in carbon from their environment. When they die or are cut down, this process stops. By analyzing the ratio of carbon isotopes in a sample of organic tissue, and then comparing it to a lot of historical references, researchers can estimate with pretty good accuracy when the processes stopped. More on carbon dating here.

Microscope image of a wood fragment from the Norse layers at L’Anse aux Meadows. Image credits Petra Doeve.

What allowed the team to reach such an accurate result in the case of these pieces of wood were “sudden increases [in the production of the 14C isotope] caused by cosmic radiation events”. This increase has been documented occurring “synchronously in dendrochronological records all around the world”, and is thus a very well-established and reliable event by which to date the pieces of wood. The particular marker they used here was a shift in the ratio of atmospheric carbon isotopes caused by a cosmic-ray event in AD 993.

I asked Dr. Dee what the most exciting moment of performing this research was for him, and he told me:

“Well it was pretty amazing to measure the isotope concentrations of lots and lots of tree-rings from, ultimately, three different pieces of wood from three different trees to discover they were all cut down in exactly the same year — and that year was exactly one millennium ago!”

According to the team, these results place the year AD 1021 as the new timeline for when Europe and the Americas first came into contact.

“We provide the earliest date for Europeans in the Americas. Indeed it is the only date for Europeans in the Americas before the arrival of Columbus — some 471 years later. This date also represents the first time in all of human history that the Atlantic Ocean was crossed — and humanity had travelled all the way around the globe. We think this in itself has particular significance.”

Beyond the value of these findings for historians, the paper also showcases how cosmic-ray events, despite being something completely removed from archaeology or the goings-on on planet Earth, can be used as reference points to date historical events.

The paper “Evidence for European presence in the Americas in AD 1021” has been published in the journal Nature.

Citrus fruit stands poised to make transparent wood more sustainable, stronger, and more transparent

Transparent wood is getting a citrusy update that’s poised to make it more sustainable, hardier, and even more transparent.

A piece of the new transparent wood. Image credits Céline Montanari.

First developed five years ago by researchers at the KTH Royal Institute of Technology, transparent wood is definitely an interesting material. It has many of the characteristics of regular wood (and, indeed, starts out life as such) but it’s generally stronger, more resilient, transparent, and an ok medium to store thermal energy (heat) in.

Now, new research reports how this material can be further improved with a little help from citrus-derived compounds.

Needs some lemon

“The new limonene acrylate it is made from renewable citrus, such as peel waste that can be recycled from the orange juice industry,” says Céline Montanari, a Ph.D. student at the KTH Royal Institute of Technology and lead author of the study.

The process of making transparent wood involves chemically stripping lignin out of wood. Lignin is a natural polymer that plants such as trees use to give their tissues mechanical strength, but it’s also the main light-absorbing compound in there. The empty spaces left over after all this lignin has been removed are later filled in with another transparent compound to restore the material’s strength while allowing light to pass through.

At first, fossil-based polymers (such as synthetic resins) were used for this role. The new paper reports on an alternative to these polymers: limonene acrylate. This is a monomer (individual building blocks of polymers) produced from limonene, which is, in turn, available in the oils found in citrus fruits.

Transparent wood created using the new approach offers much improved optical properties — a “90% optical transmittance” through a plate 1.2 mm thick and a haze of only 30% — the team explains. Unlike other similar composites developed over the last 5 years, transparent wood produced using limonene acrylate is strong enough (and intended to be used) for structural use such as girders or beams. It’s also more sustainable than previous incarnations of the material.

“Replacing the fossil-based polymers has been one of the challenges we have had in making sustainable transparent wood,” Professor Lars Berglund, the head of the KTH’s Department of Fibre and Polymer Technology and corresponding author of the study.

The material requires no solvents to produce, and all the compounds used in the process are derived from biological raw materials. The novel way this material interacts with light further opens new possibilities in fields such as wood nanotechnology, he adds.

“We have looked at where the light goes, and what happens when it hits the cellulose,” Berglund says. “Some of the light goes straight through the wood, and makes the material transparent. Some of the light is refracted and scattered at different angles and gives pleasant effects in lighting applications.”

The team is now hard at work exploring some of these potential applications.

The paper “High Performance, Fully Bio‐Based, and Optically Transparent Wood Biocomposites” has been published in the journal Advanced Science.

Researchers find a way to grow wood in a lab, and it could curb global deforestation

You’ve probably heard about lab-grown meat, sparing animals from slaughter, and lowering greenhouse gas emissions. Well, it turns out this isn’t the only thing researchers are trying to recreate at a laboratory. A team at MIT in the United States is already working on “growing” wood without relying on sunlight or even soil.

Image credit: Flickr / Chuck Coker

The process is strikingly similar to lab-grown meat. The researchers create structures made of plant cells that mimic wood, but without having to clear down forests. The cells don’t come from trees but instead from a flowering plant called Zinnia originally from Mexico. They are then turned into a rigid structure using plant hormones. They essentially “grow” the wood.

They chose the Zinnia plant because it grows fast and is well studied. The cells reproduced before being transferred to a gel for further development. Once they grew in volume, the cells were tested against different variables such as pH and hormone concentration. It will be a long road to make this cost-effective but the work represents a starting point for novel approaches to biomaterial production, reducing the environmental pressure from forestry and agriculture.

Between 1990 and 2016, over 500,000 squared miles of forests were lost due to wood consumption and the clearing of wooded areas to access arable lands.

The researchers highlighted a number of inefficiencies inherent to agriculture and forestry, some that can be managed such as fertilizer draining off fields, and some that are out of the control of the farmer, such as weather and seasonality. Also, only a fraction of the harvested plant ends up being used for food or materials production.

“The way we get these materials hasn’t changed in centuries and is very inefficient. This is a real chance to bypass all that inefficiency,” Luis Fernando Velásquez-García, who is overseeing the MIT research, said in a statement. “Plant cells are similar to stem cells in the sense that they can become anything if they are induced to.”

To achieve wood-like properties, the researchers used a mix of two plant hormones called auxin and cytokinin. They varied the levels of these hormones so to control the cell’s production of lignin – an organic polymer that gives wood its firmness. The cellular composition and structure of the final product were assessed using fluorescence microscopy.

The researchers acknowledged that they are in a very early stage with these lab-grown plant tissues. They have to keep working on the specifics, such as the hormone levels and the Ph of the gel. “How do we translate this success to other plant species? It would be naïve to think we can do the same thing for each species,” Velázquez-García said in a statement.

David Stern, a plant biologist and President of Boyce Thompson Institute, who was not involved with the research, told Wired that scaling up the study would take “significant financial and intellectual investment” from government and private sources. “The question is whether the technology can scale and be competitive on an economic or lifecycle basis,” he added.

The study was published in the Journal of Cleaner Production.

A new study on biomass fuel says smoke is more damaging to lungs than we assumed

Biomass cooking fires can incur “considerable damage” to the lungs of people who use them, a new study reveals. This effect is caused by “dangerous concentrations” of pollutants and bacterial toxins released during the burning of plant matter.

A biomass-fueled kitchen of one of the participants.

Roughly 3 billion people the world over still use biomass fuel for cooking, such as dry brush. This is making a significant contribution to the number of deaths related to household air pollution — an estimated 4 million annually. Governments around the world have launched projects to support the transition towards cleaner cooking fuels, such as liquefied petroleum gas, but economic and social factors, alongside faulty education on the benefits of this transition, means that many fires still burn on wood or brush.

Smokey issues

“It is important to detect, understand and reverse the early alterations that develop in response to chronic exposures to biomass fuel emissions,” said study co-author Abhilash Kizhakke Puliyakote, Ph.D., a postdoctoral researcher from the University of California San Diego School of Medicine.

The team used computer tomography scanners to analyze the lungs of 23 people who cook with wood biomass fuels or liquefied gas from Thanjavur, India. They also took air samples from their homes (which they used to measure pollutant concentrations there) and studied the lung function of the participants through traditional testing methods (such as spirometry). The scans were used to make quantitative measurements, so the team would, for example, take a scan when a person inhaled and another one when they exhaled, so they could measure the difference.

All in all, those who cooked with wood biomass were routinely exposed to higher levels of pollution and bacterial endotoxins. They also showed a much higher quantity of air trapping in their lungs, which is associated with lung diseases. Among the group, some participants had very high levels of air trapping and also showed abnormal tissue mechanics in their lungs, even when compared to their peers. This subgroup (around 30% of all biomass-burners) had more than 50% of the air they inhaled ending up trapped in their lungs.

“Air trapping happens when a part of the lung is unable to efficiently exchange air with the environment, so the next time you breathe in, you’re not getting enough oxygen into that region and eliminating carbon dioxide,” Dr. Kizhakke Puliyakote said. “That part of the lung has impaired gas exchange.”

“This increased sensitivity in a subgroup is also seen in other studies on tobacco smokers, and there may be a genetic basis that predisposes some individuals to be more susceptible to their environment”.

Smoke tended to affect the small airways of the lungs of participants, the authors explain, although the exact process is not yet clear. The study focused on cooking and biomass-fueled fires, but the findings are applicable to smoke from any source. Furthermore, the authors say that conventional testing has underestimated just how damaging smoke is to the lungs.

“The extent of damage from biomass fuels is not really well captured by traditional tests,” Dr. Kizhakke Puliyakote said. “You need more advanced, sensitive techniques like CT imaging. The key advantage to using imaging is that it’s so sensitive that you can detect subtle, regional changes before they progress to full blown disease, and you can follow disease progression over short periods of time.”

It is “crucial” for anyone who is exposed to biomass smoke for any extended duration to have a complete assessment of lung function by healthcare professionals to ensure that any potential injury can be resolved with appropriate interventions,” he adds. With the blaze of wildfires we’ve seen this year, this probably means that many, many people need to get their lungs checked.

The findings have been presented at RSNA 2020 – Radiological Society of North America Annual Meeting in Chicago.

Wooden buildings could help stabilize the climate

Replacing steel and concrete with wood could help in our efforts to stabilize the climate, a new paper reports. The shift would slash emissions generated by the production of such materials and further acts as a carbon sink.

Image via Pixabay.

Despite the advantages of using wood over other materials in construction, the findings should be taken with a grain of salt: harvesting enough timber for all buildings could place huge pressure on the environment. The authors thus caution that sustainable forest management and governance is key to the success of such a shift.

Going back to the basics

“Urbanization and population growth will create a vast demand for the construction of new housing and commercial buildings — hence the production of cement and steel will remain a major source of greenhouse gas emissions unless appropriately addressed,” says the study’s lead-author Dr. Galina Churkina from the Potsdam Institute for Climate Impact Research in Germany (PIK).

For the study, the team analyzed four different scenarios spanning thirty years into the future. The business as usual scenario considered that only 0.5% of all new buildings constructed by 2050 will be made out of timber. The second and third scenarios considered that figure to sit at 10% and 50% respectively, to simulate a mass transition towards timber. The final scenario considered that 90% of all new buildings will be constructed out of wood, simulating what would happen if even underdeveloped countries make the transition towards this building material.

The first scenario could store around 10 million tons of carbon per year, while the last would be close to 700 million tons. The team explains that reductions in cement and steel production would help further reduce emissions, which currently sit at around 11,000 million tons of carbon per year. Assuming that steel and concrete would still be in use (scenario 2 and 3) and assuming an increase in floor area per person, as has been the trend up to now, the team estimates that timber buildings could slash up to 20% of the CO2 emissions budget by 2050 by reducing emissions from building material manufacturing. The carbon budget is the quantity of CO2 emissions we can release and still meet the 2°C threshold set by the Paris agreement.

The authors argue that society needs some kind of effective CO2 sink to meet this budget to counteract hard-to-avoid emissions, such as those from agriculture. A five-story building made of laminated timber can store up to 180 kilos of carbon per square meter, they explain, which is around three times more than what a natural forest could hold. However:

“Protecting forests from unsustainable logging and a wide range of other threats is key if timber use was to be substantially increased,” explains co-author Christopher Reyer from the PIK. “Our vision for sustainable forest management and governance could indeed improve the situation for forests worldwide as they are valued more.”

Currently, the team estimates, unexploited wood resources would cover the demands of the 10% scenario. If floor area per person remains as it is now worldwide, the 50% or even 90% scenario could be feasible. An important goal here is to reduce the use of wood as fuel to free it up for use as a construction material.

Reducing the use of roundwood for fuel — currently roughly half of the roundwood harvest is burnt, also adding to emissions — would make more of it available for building with engineered timber. Moreover, re-using wood from demolished buildings can add to the supply.

“There’s quite some uncertainty involved, yet it seems very worth exploring,” says Reyer. “Additionally, plantations would be needed to cover the demand, including the cultivation of fast-growing Bamboo by small-scale landowners in tropical and subtropical regions.”

The paper “Buildings as a global carbon sink” has been published in the journal Nature Sustainability.

Researchers map the molecular structure of wood in bid to make it more resilient

The molecular structure of wood is what gives the material its strength and flexibility — and new research is uncovering its secrets.

New research from the Cambridge University’s Department of Biochemistry aims to understand what makes wood strong so that we know how to make it even stronger. The team hopes that their findings can guide future forestry breeding programs towards producing stronger wood than ever before — and support the renewed interest wood is receiving as an alternative building material to steel and concrete.

Wooden it be nice?

“It is the molecular architecture of wood that determines its strength, but until now we didn’t know the precise molecular arrangement of cylindrical structures called macrofibrils in the wood cells” says Dr Jan Lyczakowski, the paper’s first author from Cambridge University’s Department of Biochemistry.

“This new technique has allowed us to see the composition of the macrofibrils, and how the molecular arrangement differs between plants, and it helps us understand how this might impact on wood density and strength.”

While there is a will, we’re still lacking a way — wood simply has inferior mechanical properties to the materials we want to replace. Its main limitation comes in regards to the load bearing superstructures of major buildings. Here, wood simply can’t perform the task: it bends, and it breaks.

However, the team believes that the fault doesn’t lie with the material itself, but rather in our limited understanding of the precise structure of wood cells.

Wood is strong because each cell that makes it up is surrounded by a thick, hardy wall. This ‘secondary wall’ is constructed out of a mix of polymers, cellulose, hemicellulose, further reinforced with lignin. The team, which also included members from Cambridge University’s Sainsbury Laboratory (SLCU) used low-temperature scanning electron microscopy (cryo-SEM) to look at the nanoscale architecture of living tree cell walls. They were looking at the microscopic details of macrofibrils in the secondary wall, which are long molecules 1000 times narrower than the width of a human hair.

They collected samples from spruce, gingko, and poplar trees in the Cambridge University Botanic Garden. Each sample was flash-frozen to keep the cells in a life-like state, and then coated in a platinum film three nanometers thick to be viewable under the electron microscope.

“Our cryo-SEM is a significant advance over previously used techniques and has allowed us to image hydrated wood cells for the first time,” said Dr Raymond Wightman, Microscopy Core Facility Manager at SLCU.

“It has revealed that there are macrofibril structures with a diameter exceeding 10 nanometres in both softwood and hardwood species, and confirmed they are common across all trees studied.”

The researchers also looked at the secondary cell walls of thale cress (Arabidopsis thaliana), a plant that is used as a model organism in genetics and molecular biology research — the plant also showed the same macrofibril structures. Using several of these plants, each showing different mutations relating to the secondary cell wall and its formation, the team was also able to identify the role of specific molecules in the development of the macrofibrils. Based on their results, the team recommends thale cress as a suitable model for future forestry breeding programmes.

“Visualising the molecular architecture of wood allows us to investigate how changing the arrangement of certain polymers within it might alter its strength,” said Professor Paul Dupree, a co-author of the study in Cambridge’s Department of Biochemistry.

“Understanding how the components of wood come together to make super strong structures is important for understanding both how plants mature, and for new materials design.”

“If we can increase the strength of wood, we may start seeing more major constructions moving away from steel and concrete to timber.”

The paper “Structural Imaging of Native Cryo-Preserved Secondary Cell Walls Reveals the Presence of Macrofibrils and Their Formation Requires Normal Cellulose, Lignin and Xylan Biosynthesis” has been published in the journal Frontiers in Plant Science.

The new wood-mimicking material produced by researchers in China. Credit: Science Advances.

Synthetic wood is fire and water resistant

Scientists have created a new lightweight material that is just as strong as wood, yet has none of the usual drawbacks, such as vulnerability to fire and water.

The new wood-mimicking material produced by researchers in China. Credit: Science Advances.

The new wood-mimicking material produced by researchers in China. Credit: Science Advances.

In order to make synthetic wood, researchers at the University of Science and Technology of China in Hefei experimented with a solution of polymer resin, which was doped with a bit of chitosan.

Chitosan is a type of sugar derived from shrimp and crab shell waste which has many remarkable properties. For instance, studies have shown that chitosan is biocompatible, biodegradable, antibacterial, antifungal, analgesic and hemostatic (stops bleeding).

Previously, researchers found that combining chitosan with “nanofillers” makes the resulting material much stronger without taking any medicinal properties away. Chitosan together with bioactive glass nanoparticles can also be used to create synthetic bone grafts.

In the new study, chitosan proved essential. When the polymer-chitosan solution was freeze-dried, what resulted was a structure filled with tiny pores and channels supported by chitosan.

The next step was heating the resin to 200 degrees Celsius. The curing process forged strong chemical bonds that made the bioinspired material as crush-resistant as wood.

The Chinese researchers say they could make the material even stronger if they’d use faster freeze-drying and higher curing temperatures. Adding other substances to the mix, such as natural or artificial fibers, could also make the synthetic wood stronger.

There are a number of advantages to the new material. For one, it can be made in the lab relatively fast and in bulk, unlike wood which can take decades to grow. Wood also soaks up water, whereas this material repels water. During stress tests, samples of the new material which were soaked in water and strong acid for 30 days barely lost strength, whereas balsa wood tested under similar conditions weakened by two thirds and lost 40% of its crush resistance. When the bioinspired material was ignited, the fire couldn’t spread and rapidly extinguished. 

Although it might not become a popular constructions material, the wood-like material could be turned into a useful packaging. Its porosity might also make it a suitable material for insulating buildings.

The findings appeared in the journal Science Advances. 

 

The Wreck.

Novel nanocomposite material might prevent shipwrecks from rotting

Shipwrecks are coming — soon, to a museum near you. And it’s all thanks to nanotechnology.

The Wreck.

“The Wreck”, Knud-Andreassen Baade.
Image via Wikimedia.

A novel approach hopes to turn the damp, pitted wood of ancient shipwrecks into a showstopper. The team is currently using ‘smart’ nanocomposites to conserve the 16th-century British warship, the Mary Rose, and its artifacts. Should the process prove effective, museums will be able to display salvaged wrecks in all their glory without them rotting away.

The old that is strong does not wither

Thousands of shipwrecks have come to rest on ocean floors through the centuries. These drowned leviathans spark the passion of both researchers — who can learn a lot about past battles and ways of life from the wrecks — and public alike.

However, it’s very risky to go in and try to recover shipwrecks. Metal ships tend to weather the years underwater with some grace, but the wooden ones quickly rot away — after roughly a century, the only parts that remain are those that were buried in silt or sand soon after the sinking. Even worse, these timber skeletons quickly deteriorate once brought up to the surface.

While underwater, sulfur-reducing bacteria from the sea floor move into the wood and secrete hydrogen sulfide. This reacts with iron ions (rust) from items like nails or cannonballs, forming iron sulfide. This compound remains stable in environments that sport low levels of oxygen but binds with the gas to form acids that attack the wood.

In a paper being presented today at the 256th National Meeting & Exposition of the American Chemical Society (ACS), one team of researchers detail their efforts to keep wooden shipwrecks intact after recovery.

“This project began over a glass of wine with Eleanor Schofield, Ph.D., who is head of conservation at the Mary Rose Trust,” recalls Serena Corr, Ph.D., the project’s principal investigator.

“She was working on techniques to preserve the wood hull [of the Mary Rose] and assorted artifacts and needed a way to direct the treatment into the wood. We had been working with functional magnetic nanomaterials for applications in imaging, and we thought we might be able to apply this technology to the Mary Rose.”

Mary Rose.

Mary Rose in its specially-designed building at the Historic Dockyard in Portsmouth, United Kingdom.
Image via Wikimedia.

The Mary Rose was one of the first sailing ships built for war. Work on the wooden carrack (three-masted ship) began in 1510, and she was set to sea in July 1511. She remained one of the largest ships in the English navy for over three decades, during which she fought against the French, Scottish, and Brythonic navies — a task at which the Mary Rose excelled. The ship bristled with heavy cannons that popped out from gun-ports (which were cutting-edge technology at the time), and one of the first ships in the world capable of firing a full broadside.

Still, for reasons not yet clear, the ship sank in 1545 off the south coast of England. It was re-discovered in 1971 and recovered in 1982 by the Mary Rose Trust, along with over 19,000 artifacts and pieces of timber. The wreck helped provide a unique snapshot of seafaring and daily life in the Tudor period. It was displayed in a museum in Portsmouth, England, alongside the recovered artifacts.

Only 40% of the initial wooden structure survived the centuries underwater, and even this was rapidly degrading on the surface. So the Trust set out to preserve their invaluable wreck.

Corr’s goal was to avoid acid production by removing free iron ions from the wreck. She and her team at the University of Glasgow started by spraying the wood with cold water to keep it from drying out, which prevented further microbial activity, they explain. Afterward, they applied different types of polyethylene glycol (PEG) — a common polymer —  to the wreck. The PEG replaced water in the wood’s cells, forming a more robust outer layer.

The team, alongside researchers from the University of Warwick, are also working on a new family of magnetic nanoparticles to help in the conservation effort. They analyzed the sulfur species in the wood before the PEG treatment was applied, and then periodically as the ship dried.

This process will help the team design new targeted treatments to scrub sulfur compounds from the wood of the Mary Rose.

The next step, Schofield says, will be to use a nanocomposite material — based on magnetic iron oxide nanoparticles coated in active chemical agents — to remove these sulfur and iron ions. The nanoparticles will be applied directly to the wood and later guided through its pores to any particular areas using external magnetic fields. Such an approach should allow the team to completely remove the ions from the wood, they say.

“Conservators will have, for the first time, a state-of-the-art quantitative and restorative method for the safe and rapid treatment of wooden artifacts,” Corr says. “We plan to then transfer this technology to other materials recovered from the Mary Rose, such as textiles and leather.”

The paper “Magnetic nanocomposite materials for the archeological waterlogged wood conservation” has been presented today, Tuesday 21th August, at the 256th National Meeting & Exposition of the American Chemical Society (ACS).

Tokyo announces plan to build 350-meter skyscraper made from wood

A skyscraper is set to become the tallest timber structure in the world. The 350 meter (1,148ft), 70-floor construction will tower over Japan’s capital as a lighthouse of environmentally-friendly building. However, construction isn’t scheduled to start until 2041.

How the skyscraper will look like. Image credits: Sumitomo.

Architects have become more and more passionate about timber constructions, and Tokyo has more than its fair share of wood structures. In fact, a law passed in 2010 mandates that all public buildings of three stories or fewer need to be built primarily from wood — but skyscrapers are a completely different story.

The new project belongs to a wood products company Sumitomo Forestry Co, who also maintains a significant part of Japan’s forests. The construction will commemorate Sumitomo’s 350th anniversary.

The W350 tower will be mostly wood and 10% steel. Image credits: Sumitomo.

Sumitomo says the new structure, which they call the W350 Project, will be an example of “urban development that is kind for humans,” adding natural wood, greenery, and biodiversity to an otherwise grey and overly urban area.

The new building will be built almost exclusively from wood, using just 10% steel. The internal framework (columns, beans, etc) will be made from a wood-steel hybrid material, designed to withstand Japan’s extremely high rate of seismic activity. The Tokyo-based architecture firm Nikken Sekkei will contribute to the design.

Sumitomo’s plan also takes advantage of the fact that Japan’s forest cover is one of the most impressive in the world, and that the country’s wood stockpile is increasing each year. In a press release, they say that the project will not only be aesthetically pleasing and environmentally friendly, but it could also inject new life into an already mature economy. W350, they say, will popularize timber architecture, jumpstarting a revitalization of the forestry industry and sparking new interest in reforestation.

“The project offers the advantages of the re-use of timber, urban development that is kind for humans, and the vitalization of forestry. Wooden construction will increase through the optimal use of the strengths of trees.”

“We will make every effort to further enhance fire and seismic resistance as well as durability, thoroughly reduce construction costs, develop new materials and construction methods, and develop trees that will be used as resources.”

“We will strive to create environmentally-friendly and timber utilizing cities to Change Cities into Forests.”

Image credits: Sumitomo.

The 70 stories will provide 455,000 square meters in floor space, which will house shops, offices, a hotel and residential units. The facades will be covered in relaxing gardens and terraces. W350 will use more than 6.5 million cubic feet of wood

However, this innovative plan comes at a cost — Sumitomo will pocket an estimated ¥600bn (£4.02bn), almost double that of a conventional high-rise building. However, since construction won’t actually start by 2041, the company says that technological advancements will significantly lower this cost.

Superdense wood.

Strong as steel and lightweight? Must be superdense wood

American researchers are giving the term hardwood a whole new meaning. They have developed a relatively simple, boil-and-crush technique to make “superdense” wood — a strong but lightweight material which could be used to build everything from bridges to cars.

Superdense wood.

The wood-compacting process crushes gaps between cell walls in natural wood seen in the scanning electron microscopy image on the left), making densified wood (right) as strong as steel.
Image credits J. Song et al., Nature, 2018.

People have built and crafted with wood since times immemorial, and for good reason: it’s a plentiful, cheap, readily available building material (in most parts of the world), it’s got a good blend of strength and flexibility, and it’s relatively easy to work with. It also, to me at least, looks quite nice. Our relationship with wood as a building material, however, started to taper out with the industrial revolution, and today, it’s more of an occasional fling on the side than anything serious.

Old log, new tricks

Which is actually quite sad, as although wood lagged behind in the “strength” department, all its other qualities are still there. In a bid to put the spark back in this old flame, a team of US researchers has developed superdense wood — a highly-compacted wood that’s about as strong as steel, but much more lightweight.

The enviable physical properties of this material can be traced back to its production. It is constructed by boiling regular blocks of wood in a water-based solution of sodium hydroxide (lye) and sodium sulfite. These chemicals remove part of the lignin and hemicellulose in the wood (two organic compounds that give wood its structure and rigidity), making it more malleable.

This limbered-up lumber is then pressed at 5 megapascals (50 times the atmospheric pressure at sea-level) between two metal plates heated to 100° Celsius (212° F). The process squishes all the gaps between cells in the wood, shrinking the block to about 20% its initial thickness and increasing density three-fold.

With great squish comes great power, however: mechanical testing revealed that ultradense wood produced in this manner can withstand being stretched or pulled 11.5 times harder than the original without breaking. This would make it comparable to steel in strength, although it’s also more lightweight. The team also tested typical and superdense wood planks against stainless steel pellets fired from an airgun at 30 meters (98.5 feet) per second. The pellets went clean through the natural wood, but got lodged in the stack of densified wood of the same thickness, as you can see below:

Another advantage of the process, notes co-author Teng Li, a mechanical engineer at the University of Maryland in College Park, is that the chemicals used to scrub lignin and hemicellulose from the wood won’t pose any significant pollution concerns. In light of that fact, and of wood’s comparatively low environmental impact and sustainability, superdense wood could become an eco-friendly alternative to steel or other metallic alloys for construction works. Alternatively, it could be used in the manufacturing of more light-weight, more fuel-efficient vehicles, he adds.

As a final morsel for thought: wood is, ultimately, a form of carbon storage — plants, after all, scrub carbon from the atmosphere to grow. Viewed in this light, using superdense wood as a building material on a wide scale could help us hit two birds with one stone (if it’s harvested sustainably, of course). On one hand, it would help reduce carbon emissions from metal and non-metal mining and refining. On the other, it would capture some of the CO2 that’s already floating around. We can even make the window panes out of wood!

With the climate woes we’re facing, and those waiting for us in the future, we’ve got very few such stones to throw — and we need to get as many birds as we can.

The paper “Processing bulk natural wood into a high-performance structural material” has been published in the journal Nature.

Parasitic wooden cubes level up 1970s Parisian building with more space, more energy efficiency

“Parasite” wooden cubes may help extend the livelihood of old buildings by increasing available space and improving energy efficiency. The cubes were designed by architect Stéphane Malka as part of the Plug-in City 75 project and will be attached to the facade of a 1970s-era Parisian building slashing its annual energy consumption by roughly 75 percent.

Faced with gloomy, cramped apartments and poor energy efficiency of a by-gone era of building, the co-owners of a Parisian building in the city’s 16th arrondissement asked Malka to spruce up their property. It’s just one of many buildings facing these issues in Paris, but since the city’s building laws are quite restrictive and do not allow for the building to be raised to make way for better, more efficient space, he couldn’t just tear it down and replace it.

So he decided to level it up. And what better way to do that than with a class of modular add-ons that also look really cool?

Companion Cubes

Malka designed a type of “parasitic architecture” to solve both problems at the same time. The design calls for a series of bio-sourced wooden cubes to be mounted onto the structure — extending the useful space horizontally through openings in the exterior.

This extension would also reduce the total energy consumption of the building by a factor of four — its current consumption of 190KWh/sq. meter would drop significantly, to 45KWh/sq. meter.


These cubes will be made from a lightweight-but-strong mix of wood particles and chips which can be easily transported and assembled on site by workers.

Once affixed to the building, they will not only increase living space and allow more light to enter the building, but also allow for an inner garden courtyard on the first floor. The new facade will also be draped with hanging plants, which will make it even prettier.

Harvesting sustainable wood for guitars: Mahogany

This article is part of a series originally published by the World Resources Institute by Austin Clowes. You can read the entire series here.

Building a sustainable guitar

 

A guitar is useless unless it plays perfectly. Even the most beautiful woods can’t make up for poor construction, and the materials chosen ultimately have to serve a practical use. One of the most important parts of the guitar is the neck, which has to stay absolutely stable over years. If the neck bows too far in one direction or the other, the instrument becomes unplayable. The best guitar necks are made of mahogany. The reddish-brown wood has an interlocking grain that makes it especially resilient to changes in humidity and temperature, which would cause other woods to shift over time.

What Is Mahogany?

Genuine mahogany (Swietania macrophylla) is native to Central and South American rainforests, and is central to the colonial history of that region. Designers like Thomas Chippendale brought fine mahogany furniture to Europe, and the exotic timber caught the world by storm. The wood became such a part of Central American history that the flag of Belize still features two loggers underneath a mahogany tree.

Many slave ships were made from mahogany, and the word mahogany stems from the Yoruba language. Photo by Ben Fredericson (xjrlokix)/Flickr

Many slave ships were made from mahogany, and the word mahogany stems from the Yoruba language. Photo by Ben Fredericson (xjrlokix)/Flickr

While mahogany has a long colonial history, its sharp decline started in the 1950s as demand from the growing American middle class skyrocketed. At that time, guitar companies saw their market grow exponentially, but they also saw their costs rise as high-quality mahogany became even scarcer.

Between 1950 and 2003, over 70 percent of the world’s genuine mahogany was cut. This prompted CITES – the Convention on International Trade in Endangered Species – to finally protect mahogany by restricting trade. In light of this regulation, manufacturers took two approaches to meet demand:

  1. Use more plentiful alternatives to genuine mahogany
  2. Support sustainable community forestry in Central America

African Alternatives?

Today, the term “mahogany” encompasses a wide range of tree species that span the globe. Each of these species is equally equipped for instrument making. Woods from the Khaya genus, native to the Congo Basin and Western Africa, are now as common on guitars as genuine mahogany from Central America. African mahogany is relatively cheap and abundant, and the available wood is often equal or superior to the Central American trees that remain. These woods resemble their Central American counterparts in both form and function, but grow so quickly that they can meet demand without severe threats to the environment. Likewise, plantations in Fiji are now supplying large amounts of quality mahogany, but at a sustainable pace.

A mahogany guitar neck typically houses a metal “truss rod” for added stability. Photo by Boyd/Flickr

Making the Future in Guatemala

Many guitar makers have taken a stand to support sustainable community forestry programs in Central America as well. Bedell Guitars, for example, sources its mahogany exclusively from a well-respected concession in the Peten Region of Guatemala. Since their founding over 15 years ago, these areas have had a deforestation rate of nearly zero. Taylor Guitars relies largely on cooperatives in Honduras for sustainable and legal mahogany. Selective harvesting from community forest concessions in Guatemala and Honduras enables the production of fine guitars while contributing to local livelihoods and combatting illegal logging.

Martin Guitars supports sustainable mahogany from several concessions, and has embraced Forest Stewardship Council (FSC) and Rainforest Alliance certification. Martin even offers instruments that exclusively use FSC-certified woods. These external audits help Martin maintain high environmental standards while also reassuring consumers about their purchase. Gibson Guitars is also a large proponent of FSC-certified mahogany as an effective tool for businesses to promote sustainable use and impact local livelihoods.

The Peten region of Guatemala contains this UNESCO World Heritage Site. Photo by Adam Jones/Flickr

The guitar industry has set a great example with mahogany. Manufacturers are taking serious measures to harvest sustainably and to combat illegal logging. In the process, they are increasingly helping local communities build industry and wealth. Illegal logging is ultimately bad for everyone, and guitar manufacturers are investing in long-term solutions to the problems that cause it. As consumers, we can show our support for forests through our purchases. Luckily, mahogany has success stories in the making, but now the onus is on consumers to make informed choices when they buy instruments.

Forests around the world — including those that provide tonewoods for musical instruments — face threats of illegal logging and overharvesting. The guitar industry has already proven its ability to shift supply chains and to offer a more sustainable and transparent product. Now, the pressure for change must come from informed, conscious consumers.

The world’s tallest timber building opens in Canada – ahead of schedule

The towering Brock Commons, made completely from timber, were just completed, becoming the world’s biggest structure made from wood.

The wooden skyscraper was constructed ahead of target. Image via Acton Ostry Architects, who developed the project.

The building is part of a University of British Columbia campus, serving as a student housing hall. It will house 404 students in 272 studios and 33 four-bedroom units, and feature study and social gathering spaces for upper-year and graduate students. There will also be a ground-floor lounge and study space for commuter students. Students will pay the same for rent at the wood building as in other similar accommodations at other student residences.

The 18-story building will also serve as a proof of concept, showing that wooden skyscrapers can become a common occurrence.

Wood is a sustainable material which is not only renewable but also stores carbon dioxide instead of emitting it, like concrete buildings.

“This project should effectively demonstrate that mass wood structures can be commonplace,” said Russell Acton, principal architect on the project.


However, not all of it is built from wood. The building’s base and two cores are made of concrete, especially because regulations limit wooden buildings to six floors. After its completion, the $51.5-million residence building stands 53 meters tall (about 174 feet). The cost is a bit higher than with concrete buildings, but not by much (approximately 8%). This is not prohibitive and we can expect other wooden skyscrapers to pop up, given their environmental advantages. Furthermore, if the residence is successful and other players are attracted to the market, then increasing demand will bring down the prices, making them competitive with conventional, concrete-based buildings.

“(As) a building like this becomes a reality, it really paves the way for additional projects across the country, probably throughout North America and throughout the world,” said Lynn Embury-Williams, executive director of the Canadian Wood Council’s Wood Works BC program, who worked on the project.

John Metras, managing director of UBC Infrastructure confirmed that the construction was completed ahead of schedule. After work started in last November, it took less than a year to finish everything.

“Construction just went really smoothly. It was well designed and the construction sequence went smoothly.”

Of course, architects were eager to ease worries regarding fires, so aside from applying an anti-flammable treatment to every bit of wood used in the structure, they fit a sprinkler system at every level and encapsulated the wood in drywall and concrete.

GeoPicture of the Week: Petrified Wood

Petrified log at the Petrified Forest National Park. Photo by Joe Sullivan.

Just like a number of creatures, wood can fossilize too. Wood petrifies in very specific conditions in a two-stage process. The process starts when the plant material is buried under sediments and protected from decay by oxygen and organisms. Then, groundwater rich in minerals and dissolved solids flows through the sediments, gradually replacing the plant material with silica, calcite, pyrite or opal.

The result is as you can see here – a fossil body which often exhibits features of the wood, including the bark and cellular structures. Petrified wood can preserve the original structure of the stem in all its detail, down to the microscopic level. Structures such as tree rings and the various tissues are often observed features.

transparent wood

This transparent wood is stronger than glass

Using a chemical technique, researchers removed the complex organic polymers that give wood its characteristic appearance and, in the process, made the wood transparent. The see-through wood was then imbued with epoxy which made the material stronger than glass.

transparent wood

Credit: Advanced Materials

Earlier this year, ZME Science reported how a group from Sweden made optically transparent wood. The researchers at University of Maryland used a very similar method as their Swedish colleagues, with a couple of notable differences.

First, the lignin is removed from the wood through boiling in a chemical bath for several hours. With the lignin extracted, the woody material became transparent. Epoxy was then poured over to make the wood four to five times stronger, as reported in Advanced Materials

At this point, you might be wondering what’s the point of making wood transparent. Well, wood is a great material because of its mechanical properties, created by its structure and the interactions between cellulose, hemicelluloses and lignin. In electronics,  abundant cellulose nanofibers (CNF) and cellulose nanocrystals extracted from wood are highly sought for due to their desirable optical properties. 

The wood was boiled in water, sodium hydroxide and other chemicals. Credit: Advanced Materials

The wood was boiled in water, sodium hydroxide and other chemicals. Credit: Advanced Materials

What’s really interesting about transparent wood is that the material retains the micro-channels used to shuttle nutrients when it was a tree. This creates a waveguide effect which lets more light in. Traditional glass scatters light.

The applications could be really huge, ranging from really cool see-through furniture, to high-tech optical lab equipment. Before this happens, though, the researchers need to figure a way to scale the process because right now they can’t use the method to make transparent blocks larger than five-by-five inches.

 

KTH researchers develop transparent wood for use in building and solar panels

Wood, one of the cheapest and most widely used construction materials humanity has ever employed,  just had its range of uses expanded: researchers at Stockholm’s KTH Royal Institute of Technology developed a method that makes wood transparent. The method is suitable for mass production, making it even more attractive.

A close-up look at the transparent wood created at KTH Royal Institute of Technology.
Image credits KTH Royal Institute of Technology.

Optically transparent wood is not a new thing, says Lars Berglund, professor at the Wallenberg Wood Science Center at KTH. But it’s usually only been done in microscopic samples intended for wood anatomy studies. Their new process would allow for transparent wood production and usage on a much larger scale than anything ever before attempted.

“Wood is by far the most used bio-based material in buildings. It’s attractive that the material comes from renewable sources. It also offers excellent mechanical properties, including strength, toughness, low density and low thermal conductivity,” Berglund says.

“Transparent wood is a good material for solar cells, since it’s a low-cost, readily available and renewable resource. This becomes particularly important in covering large surfaces with solar cells.”

These transparent panels can also be employed as windows, or used to create semitransparent facades to allow light in while also maintaining privacy.

Optically transparent wood is actually a type of wood veneer from which lignin, a structurally-important component in the cellular walls of trees, is chemically removed. The resulting porous veneer substrate is saturated with a transparent polymer and the optical properties of the two materials are then matched.

“When the lignin is removed, the wood becomes beautifully white. But because wood isn’t not naturally transparent, we achieve that effect with some nanoscale tailoring,” Berglund adds.

“No one has previously considered the possibility of creating larger transparent structures for use as solar cells and in buildings.”

Wood is a renewable resource, but that doesn’t mean we’re doing it substantially  — we have to grow and harvest it accordingly, not by logging away, chainsaws blazing, at the forests around us. The KTH team is now working on ways to improve the transparency of their material and on scaling-up their production method.

“We also intend to work further with different types of wood,” Berglund concludes.

The full paper, titled “Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance” was published online in the journal Biomacromolecules and can be read here.

wooden-skyscraper

Skyscrapers made out of wood: a feeble idea or a mark of the future?

wooden-skyscraper

(c) Green

Up until the mind XIXth century most homes and buildings were made out of wood, a readily available and cheap material. However, like we all know wood is easily flammable and caused a myriad of issues, especially in urban environments. How many times were whole cities at risk of being whipped out by flames? Rome? London? Once concrete, steel, aluminium and glass buildings came into the picture though, wood was relocated to a more gentle position: furniture.

Most regulations around the world require wooden buildings to be no higher than four stories, but here comes Vancouver-based architect Michael Green into the picture with a novel, some would say feeble, idea: erecting tall buildings, as tall as 30 stories for instance, made out of wood. Before you usher the thought right out, let’s hear a bit what he’s got to say.

During Green’s 2013 TED talk, in which he lays out his plans and ideas, he boasts a rather idealistic approach – the Earth grows our food, the Earth should grow our homes too. Wait, what? How is cutting down trees for buildings ever sustainable? Well, Green argues that during the construction of buildings, 3 percent of the world’s energy is used for making steel, and 5 percent for concrete.

[RELATED] First all-wooden wind turbine installed in Germany is more eco-friendly than steel ones

By growing wood in a controlled environment and harvesting it accordingly Green claims enough wood for a 20-story building would be grown every 13 minutes. Another point he makes, one which I agree with, concerns the millions of trees that wither, die and fall to the ground around the world each year due to climate change. The pine beetle, flourishing due to warmer temperatures, has already devastated millions of acres in the Intermountain West. When a tree falls and decomposes it releases its carbon, but preserved and treated wood used for buildings would sequestrate this carbon.

Still, how do you prevent wooden skyscrapers from catching on fire from crying out loud? Green’s design is based on super-compressed mass timber panels, like Lego assemblies. This highly dense wood is extremely difficult to catch on fire (think of a huge tree stump on a fire), and coupled with coating solutions and modern anti-fire solutions, even simple sprinklers, would make these said wooden skyscrapers safe. Safety isn’t Green’s most convincing argument for bringing wood back into fashion in the constructions world, far from it – it’s necessity. An estimated 3 billion people are expected to flock to the cities in the coming decades, people that need cheap, reliable shelter.

In Sweden, a 30-story building completely made out of wood has already been approved, while Vancouver is reviewing Green’s proposal for a structure nearly as high. Read Green’s pitch on the subject at the Wood Coalition website.