Louise Bourgeois is known for her sculptures of spiders. Credit: Guggenheim Museum Bilbao.

Mother of the world's most famous giant spiders

Spiders build their webs out of their own bodies. Louise Bourgeois did the same with her sculptures. We look at how this French-American woman became an influential figure in contemporary art.V



An enormous nine-metre-high spider is on display outside the Guggenheim Museum Bilbao in Spain. Called Maman, the work is by Louise Bourgeois (Paris, 1911 - New York, 2010) and is a tribute to her mother, who was a weaver. “Bourgeois’ spiders are highly contradictory as emblems of maternity: they suggest both protector and predator,” the museum says. We explore the life and work of this key figure in contemporary art.


The sculptor who drew spiders


As early as the 1940s, the French-American sculptor was already drawing spiders. These animals occupied a central place in her work. “The spider really began as two drawings in 1947. At that time, the spider was a friendly presence. She [associated] it with eliminating mosquitoes," explains Jerry Gorovoy, Bourgeois' assistant and friend.

It wasn't until 1994 that she incorporated spiders into her sculptures. “The silk of a spider is used both to construct cocoons and to bind prey, and spiders embody both strength and fragility,” says the Guggenheim Museum Bilbao. Maman's legs resemble Gothic arches and function as “a cage and as a protective lair to a sac full of eggs perilously attached to her undercarriage.”

Bourgeois also associated the spider with her own artistic practice because this creature builds its web out of its own body. “Louise said that’s exactly what she does with sculpture. Sculpture has to come out of the body,” says Gorovoy. He explains that some of the first spiders she created represented security. To keep them from falling, they tended to be more vertical. “As she got bolder, she was able to arrange the legs and compositions that are much more dynamic,” he says. Indeed, her sculpture Spider appears to be on the move.


Spider is a bronze spider made by Bourgeois in her Brooklyn studio. Credit: Hauser & Wirth - Art Gallery


Art as therapy


According to the Museo Reina Sofia, Bourgeois' work was generated from the spaces she was inhabiting or her memory of them: her childhood in Paris, Aubusson, Choissy and Anthony; her country house in Easton (Connecticut, USA) and her studios in New York and Brooklyn. Architect and professor Beatriz Colomina explained that “those physical locations of her memory are all domestic and all associated with trauma.”

“Her work is at once deeply personal—with frequent references to painful childhood memories of an unfaithful father and a loving but complicit mother—and universal, confronting the bittersweet ordeal of being human,” says the Guggenheim Museum Bilbao. Bourgeois understood art as something curative, almost like therapy. “I know that when I finish a drawing, my anxiety level decreases. When I draw it means that something bothers me, but I don’t know what it is. So it is the treatment of anxiety,” said the artist herself.

After studying at the Sorbonne and marrying the American art historian Robert Goldwater, Bourgeois moved to New York in 1938 at the age of 27. The human body played a central role in her work. Through its representation, the artist explored universal themes such as vulnerability, identity, sexuality, violence and protection. This is evident in her series of drawings Femme Maison (1946-1947) and her sculptures Femme-Couteau (1982), Femme Maison (1983) and Spiral Woman (1984).


Bourgeois began experimenting with wood, plaster, latex and other solid materials in 1960. Credit: Tate


Throughout her career, Bourgeois received numerous honours. For example, in 1977 she was awarded an honorary doctorate in art from Yale University, in 1981 she was elected Fellow of the American Academy of Arts and Sciences in New York, and in 2003 she was awarded the Wolf Prize in the Arts, one of the most prestigious international arts awards. The sculptor died in 2010 at the age of 98, leaving behind an unparalleled artistic legacy. Her work has had a profound impact on contemporary art and continues to inspire artists and art lovers around the world.


Tungsteno is a journalism laboratory to scan the essence of innovation.

The Palace of Versailles is located about 20 kilometres west of Paris. Credit: Palace of Versailles

The secrets of the Palace of Versailles

The Château de Versailles survived the First World War and was chosen for the signing of the Peace Treaty in 1919. We explore the secrets of in this majestic place, declared a World Heritage Site by UNESCO.



Just 20 kilometres from the centre of Paris lies one of the largest and most impressive palaces in the world: the Château de Versailles. Not only was it the residence of several monarchs until the French Revolution, but it also played a crucial role in scientific research and housed vast gardens and even a menagerie with all kinds of wild animals.


A hunting lodge turned palace


The origins of the Palace of Versailles date back to the 17th century: "In 1623, Versailles was no more than a small isolated village in the middle of marshes, far from the tumult of the capital," says the Palace of Versailles websiteThen it became the hunting lodge of King Louis XIII, who ordered its construction in 1623. This building, rebuilt between 1631 and 1634 is the origin of the palace that still stands today.

The hunting lodge gradually became a pleasure palace thanks to the works ordered by Louis XIV. In 1682, it became the main residence of the royal court and the government. At times, more than 5,000 people were housed in its vast rooms. It was the residence of the French monarchy between the reigns of Louis XIV and Louis XVI, according to UNESCO"Embellished by several generations of architects, sculptors, decorators and landscape architects, it provided Europe with a model of the ideal royal residence for over a century."


The Palace of Versailles is one of the largest palaces in the world. Credit: Château de Versailles


From a menagerie to a gallery with more than 300 mirrors


The palace covers 800 hectares. The distances were so great that dishes were often served cold due to an architect’s failure to take into account the distance between the kitchen and the rooms where the food was served. This is why Louis XV decided in the 18th century to build private kitchens in his apartments. This palace even had room for a menagerie, which housed wild animals from all over the world and inspired the creation of modern zoos.

The gardens of Versailles are among the largest in the world. They have 372 statues, 55 decorative water features, 600 fountains and more than 32 kilometres of waterways. They once boasted 400 botanical species from all over the world, including pineapples, vanilla and coffee. In the 17th century, the fragrance of the flowers in the Jardin du Trianon was so intense that it could cause visitors to feel dizzy.

One of the main attractions of the palace is the Hall of Mirrors, which is adorned with 357 mirrors. In the 17th century, mirrors were considered an extremely expensive luxury. As Venice had a monopoly on their manufacture, France lured talented Venetian craftsmen and offered them the chance to create unique pieces for the palace. Legend has it that Venice, jealous of its monopoly and fearful of its production secrets being revealed, controlled the master mirrormakers and even forbade them to leave the city on pain of death.


The Hall of Mirrors is adorned with 357 mirrors. Credit: Studio McGraw


In 1833, Louis Philippe, "King of the French", decided to turn the palace into a museum "dedicated to all the glories of France". In this iconic place, unique moments in history were still to take place. The Hall of Mirrors was the scene of such iconic moments as the signing of the Treaty of Versailles, which ended the First World War in 1919. Declared a UNESCO World Heritage Site in 1979, the palace is now preparing to host equestrian events for the Paris 2024 Olympic Games.


Tungsteno is a journalism laboratory to scan the essence of innovation.

The Parthenon is considered one of the masterpieces of classical architecture. Credit: Mark Cartwright / World History Encyclopedia.

The secrets behind the Parthenon's resilience

The Parthenon has stood for over two millennia. Not only has it witnessed the glory and decline of empires, but it has also survived wars, bombings and devastating earthquakes.



The Parthenon has withstood bombardment, occupation, neglect, vandalism and even earthquakes. Over the centuries, this Greek temple located on the Acropolis of Athens has become a priceless heritage, revealing the sophisticated construction methods used in its creation. We investigate how this 5th century BC structure was built and how it still stands today.

The secrets of the Parthenon

Construction of the Parthenon began in 447 BC to honour Athena, the goddess of wisdom and war. The builders mined 100,000 tonnes of marble from a quarry about 16 kilometres from AthensWagons were used to transport the blocks, which were carved and trimmed by hand on-site with great precision. It is believed that they used a system of pulleys, ropes and wooden cranes to pull and lift the marble blocks. The structure was built in just 9 years.

Although it is considered one of the crowning achievements of the Doric order, one of the most representative architectural styles of classical Greece, it also incorporates some Ionic elements. At first sight, the Parthenon is striking in its perfection. Its lines, symmetrical columns and imposing structure convey a sense of balance and harmony. But behind this facade of perfection lies a fascinating secret: the Parthenon is not as straight as it seems.


Construction of the Parthenon began in 447 BC to honour the warrior goddess Athena. Credit: TED-Ed


A subtle and deliberate curvature


In fact, it is characterised by slight curvatures, starting from the foundation and rising along the steps, the colonnade and even the roof. To achieve this effect, the Parthenon’s architects used ingenious techniques, such as bevelling or angling the blocks of the steps, tilting the columns slightly inwards, and making the corner columns thicker.

“A building as large as the Parthenon that was perfectly straight, with perfect horizontals and perfect verticals, would appear less interesting visually than a building that has these deviations, which are at first sensed rather than actually seen or experienced,” Jeffrey Hurwit, professor emeritus of art history and classics at the University of Oregon and author of The Athenian Acropolis, tells the History Channel. The Parthenon “is a building, but it's [also] almost a sculpture.”


The Greeks applied subtle architectural techniques to create an illusion of visual perfection. Credit: History


Extraordinary earthquake resistance


If the Parthenon is remarkable for anything, it is how it has stood the test of time for more than two millenniaIn 426 BC, an earthquake struck Athens with great force. Although the Parthenon's columns shifted slightly, its structure remained intact. A group of engineers at a workshop on the Acropolis concluded that the modular columns of the Parthenon were deliberately designed to have excellent seismic properties.

Scientists from around the world have investigated the seismic resistance of the Parthenon. This structure was built on natural bedrock, which gives it a solid and stable foundation. In addition, its columns are not solid blocks, but are composed of perfectly carved and joined “slices” and there are metallic joints between the layers of marble, bonded with lead, which act as shock absorbers.


The Parthenon is still standing despite suffering several earthquakes. Credit: AP Archive


The metamorphosis of the Parthenon


Originally conceived as a temple dedicated to the goddess Athena, the Parthenon later morphed into a Byzantine church, a Roman Catholic cathedral and a mosque. It did not become a ruin until 1687. In the midst of the war between the Venetians and the Ottomans for control of the Acropolis, a fateful event marked the history of the Parthenon forever. During the Venetian bombardment, an explosion occurred inside the temple, destroying the centre of the building.

Subsequent restorations caused further damage. In 1975, an elaborate, decades-long restoration began. Every salvageable piece of marble was returned to its original position and the gaps were filled with marble from the same quarry used by the ancient Athenians. The project took more than 40 years. Today, the Parthenon attracts visitors from around the world. As well as being one of Greece's most popular tourist destinations, it is a symbol of resilience and timeless beauty.


Tungsteno is a journalism laboratory to scan the essence of innovation.

The Marina Bay Sands is located on the waterfront of Singapore's financial district. Credit: Pxhere

The secrets behind the world's most expensive buildings

The most expensive building on the planet is the Great Mosque of Mecca. It is followed by two megastructures that house luxury hotels, plus shops, restaurants and other exclusive venues. We investigate the secrets of the world's most expensive buildings.



The Great Mosque of Mecca, the Abraj Al-Bait complex in Mecca and the Marina Bay Sands in Singapore are three of the most expensive buildings in the world. Their high cost is a result of many factors, including the quality of the materials, the complexity of the design, the skilled labour required, the permits and regulations, and other unforeseen circumstances.


The Great Mosque of Mecca


The most expensive building on the planet is the Great Mosque of Mecca, also known as Masjid al-Haram. Its construction began in the 7th century AD and has undergone numerous extensions over the centuries. It is estimated that it cost around $100 billion to build this 400,000 square metre megastructure in Saudi Arabia. The most striking fact about this mosque, which is visited by millions of pilgrims every year, is that it can hold up to four million people at a time, the equivalent of almost half the population of London in one building.

According to the pillars of Islam, every Muslim who has the financial and physical means must make the pilgrimage to Mecca at least once in their lifetime. The mosque consists of rectangular central courtyard, surrounded by covered prayer areas. Those who make the pilgrimage must walk seven times counter-clockwise around the Ka'ba, a cubic stone structure in the courtyard that represents Allah's dwelling place on earth.


The Great Mosque of Mecca is the largest mosque in the world. Credit: Megaprojects


The Abraj Al-Bait


Second on this list is a megastructure also located in Mecca. The Abraj Al-Bait is the tallest skyscraper in Saudi Arabia and one of the tallest in the world. The 1.5 million square metre complex was built between 2002 and 2012 at a cost of $16 billion. At the top of the tower, which stands 601 metres tall and has more than 100 floors, is the world’s largest clock. It has four faces each with a diameter of more than 46 metres. Inside it houses a shopping centre with a capacity for 65,000 people, a prayer area and a five-star hotel.


Abraj Al-Bait is the tallest building in Saudi Arabia. Credit: Looking 4 (En)


The Marina Bay Sands


On the waterfront of Singapore's financial district stands the imposing Marina Bay Sands. These three gigantic skyscrapers, connected by a single roof, were designed by architect Moshe Safdie. They were built between 2006 and 2010 at a cost of around $6.2 billion. Covering an area of 845,000 square metres, the complex houses a 2,560-room hotel, a convention centre, shops, restaurants, theatres, museums and a casino. The hotel has two exclusive suites, each measuring 629 square metres. According to its creators, this is the equivalent of more than two tennis courts.

The owners claim that "the three iconic towers are among the most complex buildings ever built." Each has sloping and straight sections. The three meet at a height of 195 metres, creating a 9,941 square metre elevated park known as Sands SkyPark. The construction of this part of the Marina Bay Sands was one of the "most complex and challenging" phases of project. More than 7,000 tonnes of steel were pre-assembled at ground level in 14 individual pieces. Each piece was hoisted 200 metres using strand jacks, "more commonly used in bridge construction." Sands SkyPark features a public observatory, jogging tracks, gardens, restaurants, lounges and an infinity pool.


The Marina Bay Sands is notable for its three towers, connected at the top by an aerial park. Credit: Details in Luxury


Some of the world’s most expensive buildings include hotels, stadiums, offices and government buildings. Examples include the Resorts World Sentosa in Singapore; the SoFi Stadium, Apple Park and The Cosmopolitan in the United States; and Palace of the Parliament in Bucharest. In addition to their privileged location, exceptional design and high-quality materials, many of these buildings have something else in common: they are symbols of luxury and exclusivity.


Tungsteno is a journalism laboratory to scan the essence of innovation.

Rem Koolhaas is renowned for his provocative style. Credit: Delirious New York: A Retroactive Manifesto for Manhattan / Wikimedia Commons

The architect who explains the chaos of New York

The architect Rem Koolhaas no longer sees New York as a physical reality, but as the epicentre of certain values that no longer resonate with him. There was a time when he fought against the idea of this great city as a lost cause. He put his reflections into an iconic book: ‘Delirious New York: A Retroactive Manifesto for Manhattan’.



Rem Koolhaas worked as a journalist before becoming an architect. Known for his provocative style, he went on to become one of the world's most influential architects. So much so that he was awarded the prestigious Pritzker Prize in 2000. His most famous works include the headquarters of China Central Television in Beijing and the Prada Foundation in Milan. But he is most famous for his book Delirious New York: A Retroactive Manifesto for Manhattan, which outlines his perspective on the chaos and vitality of this city.


The book that catapulted Koolhaas to fame


Koolhaas' writings made him famous in the field of architecture before he had completed a single building, as the organisers of the Pritzker Prize note. The Rotterdam-born architect, who spent four years of his youth in Indonesia, was a journalist in the 1960s. After graduating from the London School of Architecture Association in 1972, he received a scholarship to travel and research in the United States. It was there that he wrote Delirious New York, hailed by critics as a classic text on modern architecture and society.

In this book, Koolhaas examines New York as a metaphor for the diversity of human behaviour. In the late 19th century, the explosion of population, technology and information transformed Manhattan into a laboratory for the invention and testing of a new way of life: the culture of congestion. This culture, he says, is reflected in the city's architecture. "Manhattan," writes Koolhass, "is the 20th century’s Rosetta Stone… occupied by architectural mutations (Central Park, the Skyscraper), utopian fragments (Rockefeller Center, the UN Building) and irrational phenomena (Radio City Music Hall)…"


New York City today is a metropolis full of contrasts. Credit: Pxhere


The Chrysler Building sleeps with the Empire State Building


The iconic cover image of the first edition of this book shows the Empire State Building and the Chrysler Building lying in the same bed. This symbolic image captures the essence of the architect's approach to New York City, presenting a provocative and playful vision of architecture and urbanism. When Koolhaas wrote it, the city was in a spiral of violence and decay. But he saw it as a potential urban paradise. "It was geared against this idea of New York as a hopeless case," Koolhaas told Smithsonian magazine. "The more implausible it seemed to be defending it, the more exciting it was to write about."

The book explores in depth the chaos and complexity of New York as a constantly evolving metropolis. Although the first skyscrapers were built in Chicago, Koolhaas argues that New York became the true epicentre of urban modernity. Some critics have accused the architect of celebrating Manhattan’s congestion and lack of urban planning. His defenders argue that his analysis seeks to highlight the complexity and vitality of urban life. Today, Koolhaas' view of New York has changed. "I no longer see New York as a physical reality, but as the epicentre of certain values that I don't feel at all close to," he told Icon Design in 2023.


The architect's legacy


In 1975, Koolhaas founded the Office for Metropolitan Architecture (OMA) in London, a practice that focused on contemporary design. The firm won a competition to expand the parliament building in The Hague and a major commission to develop a master plan for a residential district in Amsterdam. Years later, the architect was commissioned to design and build the Netherlands Dance Theatre.

His most iconic works include the Austrian House, the Taipei Performing Arts Centre, the Qatar National Library and Qatar Foundation Headquarters, the Galeries Lafayette Foundation in Paris, the Prada Foundation in Milan, the China Central Television Headquarters in Beijing and the Seattle Central Library. He also published the mammoth book S, M, L, XL in 1995. In it, he summarised OMA's work in what he called a "novel about architecture," which includes thoughts, plans, photographs, essays and writings of fiction.


The headquarters of China Central Television in Beijing is the work of architects Rem Koolhaas and Ole Scheeren. Credit: Wikimedia Commons


Despite the success of Delirious New York and his long career as an architect, Koolhass, 79, says he has never had it easy: "We have never been able to turn clients away. We've never had that moment of guaranteed peace of mind. And I think it's because, as well as bringing an interest in architecture, we were at the same time imparting criticism, which made our approach less attractive to many clients. We probably scared off as many as we attracted," he says.


Tungsteno is a journalism laboratory to scan the essence of innovation.

An uncrewed ocean mapping vehicle has discovered a seamount taller than the Burj Khalifa. Credit: Saildrone / Wikimedia Commons

A seamount taller than any skyscraper

Although the ocean covers around 71% of the Earth's surface and is the largest ecosystem on the planet, it is still largely unknown to humans. Several missions are underway to unlock its secrets One of them has found something remarkable: an underwater mountain taller than any skyscraper.



Only 5% of the ocean has been explored and mapped by humans, according to UNESCOAn autonomous ocean mapping vehicle has identified a previously unidentified seamount that is larger than the tallest building on Earth. These geological formations could serve as a reference point for different habitats and the search for previously unknown life. What is known about this mysterious mountain, taller than the Burj Khalifa?


A giant mountain hidden under the sea


The vehicle in question is called the Saildrone Surveyor, and it has spent several months surveying Alaska's Aleutian Islands and areas off the coast of California. In total, it has surveyed more than 45,000 square kilometres of ocean floor, even in 35-knot winds and waves of more than five metres. These conditions would have been "too challenging for most crewed survey vessels," according to Saildrone.

One of the most striking findings is a previously unknown seamount off the coast of California that is around 1,000 metres high. This underwater mountain is therefore taller than the world's tallest skyscraper, the Burj Khalifa in Dubai. At over 828 metres tall and 160 storeys, the structure holds several world records. As well as being the tallest building on the planet, it has the world's highest open-air observation deck and the elevator with the longest travel distance in the world.



The Saildrone Surveyor is the world´s largest uncrewed ocean mapping vehicle. Credit: Saildrone


An unexplored seafloor


"Identifying such seamounts improves our understanding of the physical processes of the ocean and identifies areas needing further exploration as unique habitats," says Saildrone. The US Exclusive Economic Zone (EEZ), which extends from the coast to 200 nautical miles from the shore, is one of the largest in the world, but much of it remains unmapped, unobserved and unexplored. "In terms of area, Alaska is by far the least mapped region of the US EEZ," says Saildrone.

Aurora Elmore, Cooperative Institute Manager at National Oceanic and Atmospheric Administration (NOAA) Ocean Exploration, says that every American, in one way or the other, depends on the ocean: "From protein from fish to feed animals or humans, to deep-sea cables that make the Internet possible. The only way the US can maximise our ocean resources is to understand what's there," she says.

During the mission, the Surveyor also carried technology from the Monterey Bay Aquarium Research Institute (MBARI) to collect environmental DNA. "Outfitted with the Environmental Sample Processor, a groundbreaking "lab in a can," the Surveyor was able to collect important clues about marine biodiversity and ocean health from the genetic "fingerprints" left behind by marine life," says Saildrone. But no specific details are offered.


The Surveyor aims to unlock the deepest secrets of the ocean. Credit: Saildrone.


Unique ecosystems on the ocean floor


The Saildrone Surveyor mission is funded by NOAA and the Bureau of Ocean Energy Management. It is the first step in mapping the seafloor of key regions in Aleutian waters at high resolution. Elmore says the advantage of the Surveyor "is getting that initial exploration step done faster, cheaper, and without as much staff."

But Saildrone is not the only project of its kind. The crew of the Schmidt Ocean Institute's research vessel Falkor (too) is also trying to unravel the mystery of the ocean floor, and has discovered several giant seamounts. "A map is a fundamental tool for understanding our planeta”locating seamounts almost always leads us to understudied biodiversity hotspots," says Jyotika Virmani, Executive Director of Schmidt Ocean Institute. "Each time we find these bustling seafloor communities, we make incredible new discoveries and advance our knowledge of life on Earth," she says.



Seamounts can host biodiversity hotspots. Credit: Schmidt Ocean Institute.


Many details about the seamounts are still unknown. But their discovery raises many questions: from how they were formed, to what kind of marine life lives on them, how they impact ocean currents, and even whether they could be a source of mineral resources. As Jamie McMichael-Phillips, project director of Seabed 2030, points out, "with 75% of the ocean still to be mapped, there is so much to be uncovered. Ocean mapping is crucial to our understanding of the planet and, in turn, our ability to ensure its protection and sustainable management."

Tungsteno is a journalism laboratory to scan the essence of innovation.

The walls of Avila are among the best preserved in the world. Credit: José Luis Cernadas Iglesias / Flickr

Three of the most impressive city walls in the world

Walls have played a very important role in human history. As well as protecting cities and their inhabitants, they have symbolised power and prestige and facilitated trade. We explore the history of some of the most impressive city walls on the planet.



The most famous wall in the world is probably the Great Wall of China. If this fortification stand out for anything, it’s for its stratospheric dimensions. It has thousands of watchtowers and collectively stretches more than 21,000 kilometres in length, which is almost twice the diameter of the Earth and half its circumference.

But this is not the only impressive wall on the planet. Many other walls surround cities and leave visitors speechless, including Avila in Spain, Ston in Croatia and Carcassonne in France.


The walls of Ávila


The walls of Ávila are among the best preserved in the world. They have a perimeter of 2,516 metres and have 87 semi-circular towers or turrets, nine gates and 2,500 merlons (vertical projections). This ancient megastructure built in a city in the centre of Spain with a population of around 60,000, has a history of more than 2,000 years. Excavations show that walls were first built in the 1st century AD, when the area is thought to have been inhabited by both the Vettones and the Romans.

The walls have undergone several reconstructions, such as those ordered by Alfonso VI (1048-1109) after the conquest of Toledo, and those ordered by Alfonso VIII (1155-1214), which are the walls that have survived to the present day. According to the Ávila tourism websiteat that time the town needed to defend itself.

"In the 16th century, they continued to fulfil the functions of health security and economic control, and reforms were carried out to repair them, but once the danger of war had disappeared, it was decided to dismantle of the additional defences (such as the barbican and the moat), which proved ineffective in the face of the military machinery of the time," they add.

At the end of the 19th century, some intellectual circles were in favour of demolishing the walls, as was being done in other European cities, as they were considered an obstacle to urban development. But the city council was determined to preserve them. The walls were declared a World Heritage Site by UNESCO in 1985, along with the old town and several churches outside the walls. Today, 1,700 metres of this megastructure can be visited.


The walls of Ávila measure 2,516 metres long and have 87 towers and nine gates. Credit: Come to Spain


The city walls of Ston


The city walls of Ston consist of the main walls and three forts, 41 towers, seven bastions, four pre-walls and a water-filled moat that extends around some of the edges. Construction began in the early 16th century in this maritime town in southern Croatia. "It took almost four centuries to finish these complex defence walls, as the builders had to adapt to the rough terrain and advancements in warfare technology," explains the official Dubrovnik heritage website.

The constant threat to the inhabitants of Dubrovnik prompted them to start building defensive walls in 1333. This construction was to become the second longest wall in Europe, after Hadrian's Wall. These walls were last used for defensive purposes in the 19th century, and are now a popular tourist destination of incalculable architectural and cultural value.


The walls of Ston are the second longest in Europe. Credit: Explore Croatia


The ramparts of the city of Carcassonne


Among the best-preserved medieval fortifications are the city walls of Carcassonne in France. Declared a UNESCO World Heritage Site in 1997, this city looks like something out of a medieval fantasy novel, according to the French National Monuments Centre. "Between the 3rd and 5th centuries, Carcassonne was attacked by Visigoths, Saracens and Franks. As a result, the city was equipped with a Gallo-Roman enclosure, featuring horseshoe-shaped towers and wide bays," they say.

In the 13th century, Carcassonne was once again besieged, this time during the bloody crusade against the Albigensians. In order to reinforce its strategic position, an extensive 1,600 metres long outer rampart was built. It was at this time that the town took on its present appearance. During the reigns of Philip III the Bold and Philip IV the Fair, the fortifications were modernised. The walls were fitted with loopholes for crossbow firing and new gates were built. Today, the two concentric walls have a total of three kilometres of ramparts and 52 towers. The views from the top are breathtaking. They include a unique panorama of the medieval town, the vineyards and the Pyrenees.


Carcassonne is surrounded by a double medieval wall. Credit: Wonderliv travel.


These are just some of the most impressive city walls in the world. Others such as the walls of Cartagena de Indias in Colombia, York city walls in the UK, or Itchan Kala in Uzbekistan should also be on this list. All of them have unique characteristics but were built with the same purpose: to protect the cities and their inhabitants from external attack.


Tungsteno is a journalism laboratory to scan the essence of innovation.

Five Measures to Valorize Construction Waste

In Catalonia, we have two pioneering projects in the implementation of circular economy measures: an office building at Plaza Europa 34 in Hospitalet de Llobregat (Barcelona) and a development of 95 multi-family homes in Viladecans (Barcelona).

For a construction project to be considered circular, it must address five aspects: meeting the three "Rs" in waste (reduce, reuse, and recycle), in addition to the use of recycled materials and the reduction of CO2 emissions.

In Catalonia, we have two pioneering projects in the implementation of these measures: an office building at Plaza Europa 34 in Hospitalet de Llobregat (Barcelona) and a development of 95 multi-family homes in Viladecans (Barcelona).

“The first project where we applied circular economy initiatives was the office building”, explains Eugenia Riqué Soriano, Head of Quality, Environment, and Energy, who is responsible for implementing circularity in construction processes.

Eugenia shared her experiences in the Circularization Program for Companies that we have underway at the Circular Economy Innovation Center (CIEC) in Madrid, where she explained the processes implemented in this building, which contributed to achieving LEED Gold certification with a very high score of 71 points.

Among the challenges overcome was the lack of space on site, for which they worked with containers to properly separate waste factions and accumulate quantity, thus filling trucks to the maximum.



"For the first time, we valorized 100% of the gypsum board scraps, returning them to the manufacturer to be recovered and reused as by-products. This prevented such waste from ending up in a landfill, as is usually the case. We accumulated the containers on each floor, storing them until we could fill a large truck and send it off. We did the same with mineral wool," Riqué explains.

"The key to everything was the involvement of supervisors and on-site personnel. It’s thanks to them that we successfully implemented these initiatives," says Riqué.

Regarding the use of recycled materials, Riqué pointed out as a novelty the use of 100% recycled sand from the demolition of other projects, which was incorporated into the mortar screeds of the different floors. "For me, it was a milestone: the easiest thing is to extract from quarries, although I encountered some resistance, we were able to demonstrate that it's just as good."



Pilot Project in Viladecans

Riqué is now working on the Viladecans homes, where they have proposed a pilot project to further advance circularity. "In addition to the initiatives implemented in the tower, in these homes, we are also valorizing 100% of the polystyrene and other plastics, the structure incorporates concrete with a reduced carbon footprint, we have used 100% recycled aggregate in the cladding of retaining walls, and the mortar screeds contain 100% recycled plastic fibers. The custom manufacturing of some materials also allows us to reduce waste generation," Riqué explains.

Additionally, she highlights the importance of teamwork in achieving circularity: advising, listening, and earning the complicity of staff to achieve objectives.

Sacyr has a business development model that aims to optimize resource use, reduce waste generation, and for those that cannot be avoided, process and valorize them to the maximum. All our activities are aligned with the circular economy.



  • Building
  • Households

There is a debate about the viability and sustainability of marine mining. Credit: Wikimedia Commons.

The environmental dilemma of marine mining

Norway has a reputation for environmental leadership, but its decision to approve seabed mining exploration has drawn widespread criticism. Much of the scientific community warns that the practice will lead to the destruction of ecosystems.



In early January 2024, Norway became the first country in the world to approve seabed mining exploration. The aim is to accelerate the search for metals and minerals essential to the green technology industry. This decision has disappointed many scientists and environmental organisations who believe that it will irreversibly damage biodiversity and ecosystems.


Extracting metals and minerals from the seabed


Deep-sea mining is the practice of extracting metals and minerals from the seabed. "The world needs minerals in the transition to a low-emission society," says the Norwegian government. The vote in Norway opens the door to "sustainable and responsible" exploration in an area of 281,000 square kilometres, roughly the size of Italy. Commercial-scale mining will require a further parliamentary vote.

Astrid Bergmål, state secretary at the Ministry of Petroleum and Energy, told the scientific journal Nature that the vote "does not mean extraction starts" immediately. "We have to collect more information before we can take a decision about extracting these minerals. That is what this opening is all about. It is not the same as approving extraction," Norwegian Energy Minister Terje Aasland told CNBC.

Maria Varteressian, Norway's deputy foreign minister, agrees: "Minerals will be a critical component in the new energy systems so the main question is not whether we need the minerals or not, the important question is can we produce them in a sustainable way." Several scientists have criticised the Norwegian government's decision, pointing out that it goes against the advice of the Norwegian Environment Agency, the scientific advisors of the Ocean Panel and other researchers.


Norway is looking for ways to obtain essential minerals for manufacturing batteries and green technologies. Credit: France 24 English


An "irresponsible" decision for the planet


"Researchers are both baffled and deflated by the decision," says an editorial published in NatureSome experts point out that too much is still unknown about deep-sea ecosystems. They believe that exploiting them without a full understanding of their fragility could have devastating consequences.

Anne-Sophie Roux, European deep-sea mining lead at the Sustainable Ocean Alliance, considers Norway's decision "irresponsible" and "puts a nail in the coffin" of the country's proclaimed role as a climate leader. "The goal of any exploration activities should be to better understand the scale of the environmental threats deep-sea mining poses—not to justify a practice we know will have vast negative impacts on marine life and the planet’s health," she told CNBC.

The argument that deep sea mining can be done sustainably goes against the broad consensus of the scientific literature, according to the expert: "There is no way to sustainably mine the deep sea in our current day and age, as it would inevitably lead to ecosystem destruction, species extinction, various sources of pollution and disruption of the climate ecosystemic services of the ocean."


Deep-sea mining is the practice of extracting metals and minerals from the seafloor. Credit: MIT Mechanical Engineering


The uncertain future of deep-sea mining


In addition to the fact that deep-sea mining can cause irreversible damage to biodiversity and ecosystems, it can also affect the fishing industry, create sediment plumes, damage the seabed and increase pollution. Several scientists also question the arguments that such mining will boost Norway’s economy, and that land-based supplies of metals such as manganese and cobalt (which are used in batteries and other electronics) are insufficient to support the transition to a low-carbon economy.

While Norway has a reputation for environmental leadership, its stance on environmental mining has drawn sharp criticism from much of the scientific community. "Norway’s about-face isn’t just a setback for the country’s sustainability efforts; it undermines the progress and the credibility of the Ocean Panel [a global alliance of national leaders that aims to promote the sustainable use of the oceans]," says the Nature editorial. It remains to be seen whether the government will allow deep-sea mining to move beyond the exploration phase and whether it becomes an important part of the Norwegian economy.


Tungsteno is a journalism laboratory to scan the essence of innovation.

Sacyr and Innovation, an inseparable pair

Like every year, June’s iFriday focused on internal innovation at Sacyr. Some of the supervisors of the most innovative and sustainable projects at Sacyr shared how they were developed and what their progress is like.

Last June 24, we held our last iFriday before the summer holidays, under the title “Sacyr and Innovation, an inseparable pair”. 

So far in 2022 we have had multiple innovation agents over that have served as inspiration to the company. In this first half of 2022, we spoke about gastronomic innovation with Nino Redruello, in February, some women in the STEM field visited our offices, in March, Antonio Oliva, Director of R&D at New Growing System discussed sustainable agriculture, Yaiza Rubio, from Telefónica brought us the metaverse in April, and in May, we learned about renewable energies with Gonzalo Sáenz de Miera from Iberdrola.

Like every year, June’s iFriday focused on internal innovation at Sacyr. Some of the supervisors of the most innovative and sustainable projects at Sacyr shared how they were developed and what their progress is like. 



Life HyReward

Patricia Terrero, Head of R&D+i at Sacyr Agua, presented project Life HyReward. The goal of this project is to explore how to generate electricity from brines resulting from desalination to make it more sustainable. The project seeks to assess how viable it is to settle on a new, more sustainable desalination process, combining reverse osmosis, a water desalination process that pressure filtrates salt water through membranes that do not let salt through, and reverse electrodialysis, which generates electricity from the saline gradient between two solutions with differenty degrees of salinity, like salt water and fresh water.

The incorporation of this process with conventional technologies allows to improve electricity generation in desalination processes, by recovering electric energy from the brines obtained in desalination before releasing them back into the sea, which in turn also reduces CO2 emissions.

“While our planet is called the blue planet, the availability of fresh water is very scarce, and we have a significant water deficit which is likely to aggravate in the next few years due to the effects of climate change. We need to look into unconventional resources to ensure demand supply, using desalination to obtain fresh water”, explained Patricia Terrero. 





The new hybrid process aims to be environmentally-friendly, generate clean and 100% renewable energy, without any negative consequences for the environment, contributing to reducing emissions and mitigating climate change. 
Then, Juan Pablo Antillera, Technical Director of Waste treatment of Sacyr Circular and Paloma Mingo, Manager of R&D projects of Valoriza, presented the project Microuwas-BIO.

This project seeks to design and develop a small-scale anaerobic digestor to identify and analyze the intervening microorganism colonies. This way, we achieve unprecedented levels of biotechnological control. The final goal is to increase the volume and quality of biogas and reduce the amount of waste bound to landfills and its biological and chemical reactivity. 

“This project focuses on anaerobic digestion. This project consists of the degradation of organic matter by microorganisms, always without oxygen, which on the one hand generates biogas, a methane and CO2 rich gas with high energy values, and digestate, on the other, a solid component that can be used as compost or a supplement to remediate degraded soil after composting”, clarified Paloma Mingo.

“The project has two distinct phases. As for the microorganism identification phase, we have spent the past 12 months taking samples in one of the digestors, which performs thermophilic anaerobic digestion, and is located in an eco-park in La Rioja, in a facility run by Sacyr Circular. All the samples were taken from the same digestor to assess how they evolve in time, by extracting DNA from all the samples taken over time. The results are promising, but they also give us a glimpse of how complex the ecosystem in the digestors is”, concluded Juan Pablo Antillera. 


Tunnel 4.0


Lastly, to conclude the session, Pablo García del Campo, technical director of Cavosa, and Miguel Martín Cano, Manager of innovation projects and knowledge of Sacyr Engineering and Infrastructures, spoke about Tunnel 4.0, an inititative that aims to improve the tunnel construction process through four action lines: use of live voice and data technology through tunnel lighting, machine sensorization for predictive analysis and machine monitorization, the development of real-time of excavation positioning; development of web applications to automate calculations.

Pablo García del Campo spoke of excavation control: “We’d noticed that workers couldn’t see properly while they were excavating. Without a reference, and even if they had it, they needed to wait for topographers to give the indications, which delayed works. Project Tunnel 4.0 was created to improve this process by creating a Google Maps of sorts, for the excavation equipment. This way, workers can see what their position is at any given time”.

According to Miguel Martín, one of the most dangerous and complicated tasks for geologists is to detect fissures in an excavation. “We have developed a browser and mobile app to help us recognize the majority of parameters, automate calculations and increase personnel safety. Thanks to this program, just by taking a picture, we can apply a series of filters able to define, detail and measure fissures and their size to preemptively detect them”. 

  • Tunnels
  • Waste management
  • reverse osmosis
  • Water

Orange peels to produce biofuel 

The need to manage waste and its valuation raises the opportunity for promising environmental projects, like FUELCAM, by the Universidad Politécnica de Madrid and the Universidad de Castilla la Mancha, focused on the use of hydrogenated terpenes.

The need to manage waste and its valuation raises the opportunity for promising environmental projects, like FUELCAM, by the Universidad Politécnica de Madrid and the Universidad de Castilla la Mancha, focused on the use of hydrogenated terpenes to create biofuel from orange peels or pine tree resin.

“This project originated five years ago to revalorize waste in the Castilla La Mancha region”, explains Magín Lapuerta, a professor at the Universidad de Castilla – La Mancha, where he coordinates the Grupo de Combustibles y Motores (GCM-UCLM) and assesses the Committee for the European norms on fuel. 

“The first part of this job involved working with turpentine, a terpene distilled from pine tree resin, that is after subject to hydrogenation, so that it won’t produce black smoke at combustion”, explains Lapuerta.
Then, it was the turn for orange peels, a readily available material since it is a byproduct that is not used by coopearatives and farmers. 

This project stems from David Donoso’s thesis. David is a researcher at the ETS de Ingeniería Industrial de la UCLM, that comprises three research lines with three different raw materials, the three of them terpenos hidrogenados: turpentine, hydrogenated orange oil and CST, which is sulfate turpentine, a paper industry byproduct.

“Our research confirms that fully hydrogenating fuel allows to reduce soot by 55%”, says David Donoso.



Turpentine isn’t really a byproduct. It’s extracted from pine trees, and it’s mainly used to produce substances like turpentine spirits. While its extraction would have major impact on the pine tree industry and have applications to prevent fires, this research line doesn’t show much promise.

For that reason, they focused on CST and orange peels. “The research to create fuel was done with a reactor at the Universidad Politécnica de Madrid. We created enough to burn it with an engine”, explains Lapuerta.

The fuel was tested at Castilla La Mancha mixed with diesel fuel.  In the test formulas, 20% is hydogenated turpentine or hydrogenated orange oil, and 80% is diesel. 

 “The percentage of biofuel could be raised. We give added value with the hydrogenation”, researchers say. It could also be tested in gas engines. 

“Now we need to take the leap on an industrial scale, by testing biofuels mixed with JetA1 in aircraft turbines”, explains José Laureano Canoira López, professor at the Chemical engineering area of the Universidad Politécnica de Madrid (UPM).



“We still need to find turbines to test out these results in the aviation industry. We need a refinery or biorefinery company willing to hydrogenate the materials for us and prepare a large amount to start testing on real planes”, researchers say.

However, there is a major gap that seems tough to close. In order to test out efficiently they would need to produce at least 100 liters, but for fuel companies to find the operation profitable, they would need to produce at least 1,000 liters and take the risk.

The  ASTM (American Society for Testing and Materials) lays down the possibility of using from 10% to 50% of biofuels in aviation, as long as they meet the requirements.

There are other research lines with potential. There are other types of terpene waste, such as biowaste from parks and gardens maintenance, mostly leaves, which could also be used to make biofuels. 

  • Biofuel

Climate change will increase the frequency and intensity of droughts in many regions of the planet. Credit: Unsplash

Technologies to mitigate future droughts

Ensuring a stable, high-quality and climate-neutral water supply is one of the great challenges of the 21st century. Here we examine the crucial role that technology plays in the fight against the droughts of the future.



More than two billion people were living in countries with water shortages in 2021, according to the World Health Organisation (WHO). The situation will worsen in some regions due to climate change and population growth. 

With technological advances reducing energy costs and environmental impact, desalination is presented as a possible solution to provide drinking water from the sea. To mark World Water Day on 22 March, we look at the most efficient technologies to mitigate the droughts of the future.


97% of water is in the ocean


Safe and easily accessible water is important for public health, whether it is used for drinking, domestic use, food production or recreation, as the WHO points out. 

"It is necessary to be efficient in the use of water, to reuse every last drop and, finally, to supplement it with desalinated water," says Domingo Zarzo Martínez, president of the Spanish Association of Desalination and Water Reuse (AEDyR) and Director of Innovation and Strategic Projects at Sacyr Agua.

About 97% of the planet’s water is in the ocean, according to the US National Oceanic and Atmospheric Administration. The remaining 3% is distributed in many different places, including glaciers and ice, below the ground, in rivers and lakes and in the atmosphere. 

Zarzo stresses that "we have an inexhaustible source of water that is not dependent on climatic conditions." "Therefore, the use of non-conventional resources such as desalination and reuse will go a long way towards solving water scarcity problems, and in fact is already doing so in many countries."


Intensifying droughts negatively impact water availability and quality. Credit: Sacyr


Desalination plants to combat droughts?


According to Zarzo, desalination plays a fundamental role in the fight against water scarcity. In countries such as Spain, the implementation of large desalination plants has served to "supply the Mediterranean coast with water in a safe and stable way, not only for the production of drinking water, but also for agricultural and industrial uses.

" Even so, the expert insists that the capacity is not sufficient and that new infrastructure must continue to be planned to meet current and future demand. There are 20,000 desalination plants around the world. Apart from Spain, other countries with large desalination programmes include Israel, Algeria, Australia and Saudi Arabia.

The main advantage of desalination is that it creates a new water resource from the ocean, which is an inexhaustible source and not dependent on the climate. According to Zarzo, desalinated water has "an exceptional quality and purity because the membranes prevent any kind of pollutant from entering it." It is also possible to add minerals, vitamins, electrolytes or any other necessary component to create water that is tailored to any use. In other words, "water à la carte".

"On the other hand, by using desalinated water in cities, the wastewater produced will have better characteristics (including lower salinity) for reuse," he says.

One of the drawbacks of desalinated water is that it can be more expensive than other conventional water sources. "This is a misconception, because with drought and climate change, conventional resources are becoming increasingly depleted and polluted, so these prices will even out," says Zarzo, who stresses that "there is no more expensive water than that which you don't have."


Desalination plants use a process called reverse osmosis to remove salt from seawater. Credit: Sacyr Concessions

The challenge of minimising environmental impact

The desalination of seawater produces brine, a liquid with a high concentration of salts and a negative environmental impact. "One of the aspects that most concerns the population is the discharge of the concentrate into the sea, but if this is done correctly, it has been scientifically proven that the environmental impact is totally irrelevant and, thanks to prior dilution and diffusion systems, this concentrated seawater is indistinguishable from normal seawater just a few metres from the discharge point," he says.

The decarbonisation of desalination plants is also a key challenge. Their energy consumption, especially if based on non-renewable sources, generates carbon dioxide emissions and contributes to climate change. Desalination plants are powered by conventional electricity grids, so their indirect emissions depend on the national energy model.

Zarzo points out that the desalination industry has made great efforts to improve the sustainability of plants: "In fact, almost all R&D is focused on this, from the production of renewable 'blue energy' generated by the salinity gradient between brine and freshwater, to circular economy concepts such as the extraction of elements, salts and chemical compounds from brine (so-called brine mining)."

Beyond desalination, reuse is also important: "We need to consider reusing every last drop of wastewater. In fact, more water is already reused in the world than the amount that is desalinated." There are educational and cultural barriers that hinder some uses, such as using recycled water for the production of drinking water, although this has been done for many years in California, Singapore, Israel, the Netherlands and Namibia.

Harnessing the benefits of technology is key to combating future droughts and having a stable, high-quality water supply that is not dependent on the weather: "In developed countries, we are not aware of the privilege of having safe, quality drinking water available to us in our homes on a continuous basis."

Tungsteno is a journalism laboratory to scan the essence of innovation.

Smart Geolocation in the Tunnels and Galleries of Langosteira

The intricate tunnel network requires the installation of a communication system that enables remote control and the implementation of an access and control system for workers.

The project to develop the railway access to the Exterior port of Langosteira (A Coruña), which began in 2022 and is due to finish in 2026, includes the construction of 6.7 km of railway tracks, 5.3 km of which run through tunnels.

This project was awarded to the joint venture comprising Sacyr Engineering and Infrastructure, Cavosa, and Construcciones y Obras Taboada Ramos by ADIF. It has a 48-month execution period and will be financed with Next Generation EU funds.

This link serves as a single-track railway platform for Iberian gauge cars and a maximum speed of 100 km/h. It stretches along a main axis of 5,573 meters, including three tunnels.

The intricate tunnel network requires the installation of a communication system that enables remote control and the implementation of an access and control system for workers.

Tunnel 1 has six access points. "We have designed a system that allows simultaneous communication and interconnected control of all accesses," explains Carlos Balado, Project and Site Manager.

Tunnel 2 connects the Suevos area with the inner zone of the Outer Port of A Coruña, spanning 747 meters.

To meet the requirements of this project, we have applied smart technologies to always monitor activity at the infrastructure.

A system has been implemented with an access controller that manages tamper-proof TCP communications and allows for offline operations; an IP card reader resistant to weather conditions connected to the controller, and access control software installed in the control room for all equipment.



All workers are provided with a tag that provides data through readers about their entry, exit, or location along the tunnels and galleries.

Furthermore, as a new feature, we have implemented a communications system based on the deployment of WIFI inside the tunnels and galleries, allowing for instantaneous communication with the port police's access control points.

A predefined alarm management system is also incorporated to detect the absence of staff at a certain time or to ensure that the number of people does not exceed the established limit.

The features of the proposed technology allow for connectivity and data traffic between two collateral base stations in the event of optic fiber breakage.

Five ways to improve fire prevention security measures

We believe that we need to take further steps to reduce these accidents, and we propose to implement a package of measures.

Ramón Sánchez Fernández
Director for Building Engineering 
Engineering and Infrastructure


In recent weeks, we have witnessed true tragedies in Spain with several fires in buildings as protagonists. On February 19, we learned of the death of three elderly women from smoke inhalation and burns of varying degrees due to fire at a seniors home. The investigation seems to point to the most probable cause of the fire being the explosion of a battery or electrical failure in the room where they were sleeping. However, it is suspected that fire protection and evacuation measures did not function properly, leading to this tragic ending.

On February 22, we witnessed the total combustion of two apartment buildings in Valencia in the span of just a few hours, with the sad result of 10 deaths and 138 homes consumed by flames.

The causes of the fire are unknown, but what we do know so far is that it spread very rapidly through the ventilated outer walls, also aided by the supply of oxygen provided by the strong winds that day. These events make us think that something is failing in our building stock. According to the report "Fire Victims in Spain in 2022" by APTB and the Mapfre Foundation, in that year there were 33,000 fires (requiring firefighter mobilization) in buildings in Spain, setting a record of 214 deaths, of which 176 occurred in homes.

This statistic draws attention to the number of deaths in homes, where typically -and inexplicably-, there are no fire detection systems. These systems are only installed in garages or high-risk premises. Half of the victims in care homes are senior residents, the living room is the riskiest area, and the most frequent cause of death is smoke inhalation. Secondly, unfortunately, nursing homes appear, with 16 deaths in 2022. The fire protection measures required for these types of facilities should be the same as those for a hospital, as both infrastructures are occupied by people who mostly require attention.

Among these measures are the installation of smoke detectors in rooms, portable fire extinguishers no less than 15 meters away, and manual alarm buttons in corridors and circulation areas. In high-risk areas, there are additional detection and extinguishing measures. Experience shows us that these measures are very useful in hospitals but insufficient in the case of nursing homes, whose residents have especially reduced mobility and lower cognitive abilities.

Finally, data show that in other buildings where fire protection measures are more sophisticated (automatic fire detection and extinguishing, alarms connected to firefighters), the number of victims is very low (five deaths in 2022), although the risks are high. For all these reasons, at Sacyr, we believe that we need to take further steps to reduce these accidents, and we propose to implement a package of measures:

1.    In nursing homes, install automatic detection and sprinkler systems. Ensure that proper system maintenance is carried out.
2.    In newly built residential buildings, regardless of the building's height, install smoke and carbon monoxide detectors inside the homes, as well as manual extinguishers on all floors.
3.    In existing homes, install smart smoke and carbon monoxide sensors. Use NextGen funds to expand these systems.
4.    Identify ventilated facades with insulating materials that react to fire. In these buildings, proceed to modify the facade or install automatic detection and extinguishing systems.
5.    Simplify and unify the vast amount of fire regulations that exist with the aim of conveying to the sector the importance of active and passive fire protection measures.

We need to make an effort to reduce the number of fire victims in our country.

China has built the JF-22 hypersonic wind tunnel. Credit: Chinese Academy of Sciences

World's fastest hypersonic wind tunnel

From designing return capsules for lunar missions to venturing into unknown atmospheres with interstellar exploration spacecraft, the journey of aerospace innovation is marked by a common thread: thousands of tests conducted in hypersonic wind tunnels.



China claims to now have the world's most powerful wind tunnel. The stated goal of this cutting-edge facility is to contribute to a wide range of missions, including lunar expeditions with Chinese astronauts and the development of hypersonic aircraft able to reach anywhere on the planet within an hour. 

We explore the wonders of this tunnel, which can simulate extreme flight conditions up to 30 times the speed of sound.


Flying at record speed


The tunnel is called JF-22 and is located in Sichuan, southern China. Construction began in 2018 and was completed in August 2021. "(We) have built the world’s largest free-piston driven expansion tube wind tunnel with high enthalpy," said researchers at the Hypervelocity Aerodynamics Institute, as reported by the South China Morning Post.

The Institute of Mechanics of the Chinese Academy of Sciences (CAS) in Beijing announced in June 2023 that its new JF-22 hypervelocity wind tunnel had passed an "acceptance check" and was ready for general use.

The tunnel spans 167 metres in length and can generate airflow velocities ranging from 2.5 to 11.5 kilometres per second.

 The facility’s owners claim that it can simulate hypersonic flight conditions up to Mach 30, or 30 times the speed of sound. With a generous diameter of four metres, the tunnel accommodates larger objects for more accurate flight data.

As noted by Interesting Engineering: "The diameter of an intercontinental missile is also four metres, so researchers could practically put an entire missile inside and test the impact of sending it at speeds much higher than Mach 5."


The JF-22 can simulate airflow speeds up to Mach 30. Credit: Defense Formation.


The challenges of hypersonic flight


Wind tunnels are typically used to test new aircraft, missile and spacecraft designs. Some of the most powerful tunnels, apart from the one mentioned above, are NASA’s Hypersonic Tunnel Facility in the United States, which can reach speeds up to Mach 7, and the one at NASA Langley Research Center, which can achieve up to Mach 10.

The team behind the JF-22 claims that it can be used for various engineering projects, "such as the return capsule of the lunar landing project, entry into an alien atmosphere with an interstellar exploration aircraft and the development of hypersonic vehicles, such as scramjet-powered aircraft."

The first hypersonic flight took place in 1947, led by American pilot Chuck Yeager, a distinguished fighter pilot in the Second World War. Yeager conducted numerous tests with various aircraft until he accomplished the feat of breaking the sound barrier. 

Subsequently, the aviation industry witnessed the development of increasingly advanced aircraft. Among them was the Tupolev Tu-144, hailed as the world's premier supersonic airliner. Its unveiling in 1968 marked a significant milestone in aviation history, particularly for the Soviet Union.

To achieve success, these aircraft needed to surmount various hurdles. Breaking the sound barrier often resulted in a thunderous sonic boom, creating significant noise pollution.

Additionally, the challenge of affordability was always an issue. Nowadays, supersonic flight remains predominantly within the realm of military aircraft, exemplified by the F-18 fighter jet.


The fascination with speed and space exploration has driven mankind to develop hypersonic aircraft and spacecraft. Credit: MSGT Ken Hammond


From hypersonic aircraft to spacecraft


While hypersonic aircraft are designed to fly within the Earth's atmosphere, there are craft designed to travel into space. In fact, the goal of the JF-22 wind tunnel is to "accelerate the development of a space-to-earth shuttle system," Jiang Zonglin, a researcher at the Institute of Mechanics and project manager of the wind tunnel, tells the Asia Times website. "If successful, the facility can also help reduce the cost of launching satellites and spacecraft by 90%."

Besides the inefficiency of conventional engines at hypersonic speeds, the transition in and out of the atmosphere at such velocities results in exceedingly high temperatures.

Therefore, it is essential to develop materials and thermal protection systems that can withstand these harsh conditions. It is still too early to say whether this tunnel will have a significant impact on the development of hypersonic technologies in the coming years. 

Nevertheless, it is evident that wind tunnels like JF-22 serve as invaluable tools for simulating the extreme conditions of hypersonic flight, allowing engineers to test and refine their designs without endangering lives or spacecraft.

Tungsteno es un laboratorio periodístico que explora la esencia de la innovación.

Belgium wants to build the world's first artificial energy island. Credit: Elia

An artificial island in the sea for a greener future?

Belgium has a solution for making the most of the energy from offshore wind farms: building the world's first artificial energy island. The country wants to connect offshore wind farms to the mainland with a pioneering hub in the sea.



Construction of the world's first artificial energy island looks set to begin. At the end of 2023, Belgian transmission system operator Elia announced that it had received the environmental permit to launch the projectThe planned new island, called Princess Elisabeth Island, will be an energy hub 45 kilometres off the Belgian coast, connecting new offshore wind farms to Belgium's onshore power grid.


Turning the seas into the "power plants of the future"


In December 2022, the Belgian federal government granted the project 99.7 million euros from the European Union's Recovery & Resilience Facility. According to Elia, the company behind the initiative, construction will commence early this year and last until August 2026. The island will be made of sand and surrounded by an outer perimeter of concrete caissons. Its surface area above the waterline will cover six hectares, and its total area on the seabed will extend to a maximum of 25 hectares (the equivalent of 37.5 football pitches).

The island will be located in the North Sea and will allow Belgium to access energy produced by nearby offshore wind farms, trade renewable energy with other countries and increase Europe's interconnection. Europe's seas "are becoming the power plants of the future," says Nicolas Beck, Elia's head of community relations.


The island will connect new wind farms to Belgium's onshore electricity grid. Credit: Elia


The impact of the island on the health of the North Sea


The construction of an artificial island can have a significant impact on marine ecosystems. This depends on a number of factors, such as the geographical location, the size of the island and the construction methods used. In addition to the fact that it may involve the destruction of the marine ecosystem and affect fish stocks and other marine species that depend on that habitat for their survival, it could also affect the natural flow of water and ocean currents.

The Belgian authorities have recognised that new construction and installation plans cannot afford to ignore marine life, both above and below the water. In response to these concerns, Elia says it has opted for a "nature-inclusive design" that will seek to protect and even enhance the biodiversity of the area. "Elia want to minimise the disruptive effects the island will have on the surrounding marine environment at the same time as embedding real ecological and environmental value into its project," the company says.

To this end, they have taken a number of measures. "Ledges attached to the outer storm walls will provide somewhere for the black-legged kittiwake, a vulnerable bird species, to rest and breed," says the company, which also aims to create a rich and diverse artificial reef below the waterline. For example, it will install relief panels at each of the four corners of the island. These panels will provide a three-dimensional structure to which smaller marine organisms can attach, "creating a microhabitat for marine life".


Elia has received the necessary environmental permits to build the island. Credit: Elia

It is still too early to know with certainty how the construction of this artificial island will impact the marine habitat and to what extent it will become a crucial node for offshore wind energy in Belgium and Europe. Elia, which aims to connect the full capacity of new wind farms to its grid by 2030, insists that one thing is clear: "Only through the quick and extensive development of offshore wind will Europe be able to reach net zero emissions by 2050."

Tungsteno is a journalism laboratory to scan the essence of innovation.

Florence Knoll left an indelible mark on the world of design. Credit: Knoll

The mother of modern office furniture

Florence Knoll claimed that she never set out to design furniture. She said she designed "the fill-in pieces that no one else was doing." This philosophy, born of necessity and innovation, led her to create some of the most iconic pieces of modern office furniture.



Behind the sleek, modern look of post-war corporate offices in the United States is a great woman: Florence Knoll, one of the most influential architects in the development of 20th century interior design. We explore the fascinating story of this American whose iconic designs are still commonplace in offices, homes, public spaces and museum collections.

"The fill-in pieces no one else was doing"

Despite being one of the most important furniture designers of her time, she said she never sat down to design furniture: "I designed the fill-in pieces that no one else was doing." By 1950 she had designed more than a third of the 63 products on the Knoll Associates price list. Among her creations is the Lounge Collection, designed in 1954. Her pieces, characterised by clean lines and geometric shapes, are poised on elegant metal frames.

Knoll's designs are frequently featured in international publications and are still available today. In a 1998 article, Vogue praised the Florence Knoll sofa and its transcendence from the confines of a "midtown Manhattan bank president's office with beige wall-to-wall carpeting" to "high-profile" settings such as fashion designer Tom Ford's apartment.

In 1964, The New York Times described Knoll as "the single most powerful figure in the field of modern design." The architect played a pivotal role in transforming Knoll Associates into the largest and most prestigious high-end design firm of its time. She also redefined office design with her innovative concept of "total design." Instead of traditional private offices, she proposed open-plan workspaces that facilitated collaboration and communication.

Knoll is credited with revolutionising modern office design. Credit: Casa Palacio

A new design for offices

"Once upon a time, virtually every big business executive thought his office had to have pale green walls and that his heavy desk with drawers to the floor had to be placed cater-corner [diagonally]," wrote The New York Times 60 years ago. That was until Knoll ushered in an era by proving that an office could be designed rather than decorated.

"I'm not a decorator. The only place I decorate is my own house," she said in an interview with the same newspaper. Knoll opted for vibrant colours and the iconic "Tulip chairs", which offered comfort and style. Chrome-legged desks and oval meeting tables reflected a modern, functional aesthetic. In multi-level interiors, she opted for open-riser staircases that seemed to float in the air.

She also popularised the idea of bringing art into the office. "Knoll was one of the few furniture companies in the United States to showcase contemporary art alongside Modern furniture in its showrooms, creating visual dialogues between unique works of art and mass-produced designs, an affirmation of the company's commitment to Modernism," explains architecture and design magazine Metropolis.

Knoll paid meticulous attention to every detail of the furniture. Credit: Knoll

From wire chair to 'Womb' chair

The architect became a full partner in Knoll Associates after marrying German-born furniture make Hans Knoll in 1946. After her husband's death in a car accident in 1955, she took over as president of the company. She sold her stake in the company in 1960, but continued as design director another five years. During this time, the company became one of the most influential design organisations.

In addition to her leadership, Knoll was also known for nurturing the careers of some of the most celebrated design names of the post-war era. For example, she supported sculptor Harry Bertoia during his two-year research into how to make furniture out of metal. This led to the iconic wire chairs, now regarded as Knoll classics. She asked Eero Saarinen to design a chair "like a great big basket of pillows" that you could curl up in. The result was the Womb chair, which seems to embrace the body.

Knoll died in 2019. Her legacy is reflected not only in her work, but also in the many awards she received. In 1961, she became the first woman to receive the Gold Medal for Industrial Design from the American Institute of Architects. Decades later, in 2003, then US President George W. Bush awarded her the National Medal of Arts, one of the country's highest honours for artistic excellence. The reason: an invaluable legacy in the world of design.


Tungsteno is a journalism laboratory to scan the essence of innovation.

Collecting solar energy in space and beaming it back to Earth is not without its challenges. Credit: European Space Agency

The dream of solar farms in space

The idea of putting solar farms in space has been around since at least the late 1960s. So far it has not gained sufficient traction due to cost and technological hurdles. But is it now technologically feasible?



While some researchers suggest using skyscraper lifts to save and generate energy, others are looking at ways to do it using snowmicroalgae or by equipping cruise ships with photovoltaic sailsAnother alternative that has been in the spotlight for years is solar space farms. What are the technical and economic obstacles to this energy utopia?


The quest for uninterruptible solar power


The idea behind space solar power is simple and appealing: harness solar energy in space, where it is continuously available regardless of local weather or darkness. This energy would be collected on satellites orbiting the Earth and then transmitted wirelessly to collection points on the surface. "The concept complements rather than competes with terrestrial renewables, because Space-Based Solar Power can make power available reliably on an ongoing 24/7 basis," says the European Space Agency (ESA).

ESA has signed contracts for two conceptual studies of space-based solar power plants on a commercial scale. "We are really starting from a blank sheet of paper to get an up-to-date design for what working solar power satellites could look like, sourcing promising ideas from everywhere we can, and leveraging the latest advancements in space and terrestrial technologies," says Sanjay Vijendran, ESA's SOLARIS director.


Various researchers hope to deploy solar farms in space. Credit: Euronews


The challenges of space solar farms


This idea is not new and has been around since at least the late 1960s, says Matteo Ceriotti, Senior Lecturer in Space Systems Engineering at the University of Glasgow: "Despite its huge potential, the concept has not gained sufficient traction due to cost and technological hurdles." For Ceriotti, the main limitation is the enormous amount of mass that needs to be launched into space and its cost per kilogramme. "Companies such as SpaceX and Blue Origin are developing heavy-lift launch vehicles, with a focus on reusing parts of those vehicles after they have flown." While this can significantly reduce costs, it would still require hundreds of launches.

For Ceriotti, missions to deploy space-based solar power are challenging and some risks need to be assessed. "While the electricity produced is fully green, the impact of the pollution from hundreds of heavy-lift launches is difficult to predict," he stresses. "Additionally, controlling such a large structure in space will require substantial amounts of fuel, which involves engineers working with sometimes very toxic chemicals."


Deploying solar farms in space is costly and technically challenging. Credit: SciShow Space


A proposal "more feasible and desirable than ever"


Despite these limitations, Vijendran believes there are many reasons why space-based solar power "is looking a lot more feasible and desirable than ever before." "These include the reduced cost of launch to orbit with the advent of reusable launchers, the reduced cost of satellite hardware through mass production—seen with new constellations such as Starlink and OneWeb—and trends towards very modular solar power satellite designs." In addition, space robotics and in-space assembly and servicing technologies "have really come a long way in the last two decades." According to the expert, this will be essential for the construction and maintenance of solar power plants.

It is still too early to say whether solar farms will eventually reach space. While some companies, such as Space Solar, hope to have them operational by 2035, other researchers are focusing on other alternatives, such as putting reflectors in space to allow solar farms on Earth to work longer and longer. Ceriotti admits that the challenge of building such platforms in space may seem daunting, but insists that space solar power is technologically feasible. "To be economically viable, it requires large-scale engineering, and therefore long-term and decisive commitment from governments and space agencies," he concludes.


Tungsteno is a journalism laboratory to scan the essence of innovation.

We build plants to purify polluted rivers

We have discovered an opportunity to create plants that can treat these contaminated waters and return them to the riverbed in perfect condition, even for crop irrigation.   

Abandoned mining activity generates waste in slag heaps and   sludge deposits that, over time, become a leading source of contamination in surface and groundwater. This is occurring, for example, in the Odiel river basin in Huelva. 

To solve this problem, Sacyr, the Universidad de Huelva, and Andalusia’s Regional Water and Environment Agency joined forces four years ago in the LIFE-ETAD project, 50% of which is funded by the European Commission through Life +.

Initial efforts focused on the Mina Esperanza treatment plant (TAAM project) in order to subsequently create the Mina Concepción treatment plant (as part of the LIFE-ETAD project) with new developments to improve the treatment processes and the quality of the water exiting the process. 

This technology has proven to resolve the serious problem of environmental contamination at more than 30 critical points in the mining area.  

Focus of public procurement interest in Andalusia


Due to the unique features of these highly polluted rivers, the National Hydrologic Plan postponed—until 2027—the targets of the EU Water Framework Directive (2000/60/EC), which specified 2015 as the deadline for attaining good ecological and chemical levels in European waters. 

Mining activity, especially where pyrite is concerned, creates environmental liabilities that, when abandoned by mining companies, generate acidic runoff with a high concentration of heavy metals that degrade the water quality, so there is virtually no aquatic life in these waters.

The Odiel and Tinto rivers are considered extreme cases of this kind of contamination. More than one-third of the watershed is polluted and occasionally this pollution reaches the Gulf of Cadiz and even the Mediterranean. 

“When it rains, the water filters through the materials that were once used in mining activity (abandoned mines, dumps, etc.); the metals dissolve and the water becomes acidic,” explains Francisco Javier Mateos, Project Manager for the Innovation and Knowledge area of Sacyr Construction’s R+D department. “With LIFE-ETAD, we’ve found an inexpensive technology with little maintenance and zero energy consumption that could become the focus of innovative public procurement in Andalusia,” he continues. 



How DAS technology works


Acidic water from the Mina Concepción is channeled to a pre-treatment reservoir where it stagnates and oxidizes. Iron oxidation is critical for the operation of the plant. 

It subsequently passes through three sets of reactor tanks and a settling basin at the outlet of each one. These reactors are filled with what is called Dispersed Alkaline Substrate (DAS). 

DAS is a mixture of wood ash and an alkaline reagent, such as calcite, magnesium oxide, or barium carbonate (witherite). As the water passes through the different reactors, its pH rises, causing the precipitation of divalent and trivalent heavy metals into the reactors themselves and the settling basins situated at the outlet of each. Finally, in the last reactor tank, the sulfates are eliminated, leaving the water exiting the plant suitable for irrigation. 

In recent tests, the Mina Concepción plant treated 6,860 m3 of acidic water, during which sulfate retention was 69% on average. 

“Testing has confirmed that DAS technology can be used on a large scale to passively eliminate acidity and heavy-metal/sulfate retention,” explain José Miguel Nieto and Francisco Macías, project researchers at the Universidad de Huelva, who carried out the technological process of decontaminating the water.  

  • Metal-bearing wastewaters
  • Mining
  • Contamination

Several cities are using technology to improve the quality of life for their residents. Credit: Unsplash

Top 5 most innovative technologies for smart cities

At CES, the world's biggest tech trade show, it's not all flying taxis and futuristic robots. We take a look at the most innovative gadgets for smart cities and smart homes.



A technology that turns any countertop or surface into a charger, an autonomous machine that eliminates algae harmful to water quality and a biometric solution that puts an end to privacy concerns. We take a look at the most innovative inventions for smart cities and smart homes, according to the Consumer Technology Association (CTA), the organisation that organises CES, the world's largest annual technology event.


A countertop that charges your phone


FreePower can turn any countertop into a wireless charger—from a restaurant bar to a kitchen island or home office desk. "Early adopters of wireless charging technology are probably familiar with this scenario: placing a device on your charger before you go to bed, then waking up to a dead battery because it wasn’t aligned with the charger’s ‘sweet spot’," say the creators. Their technology features a free-standing architecture that does not require precise alignment. In other words, the user can avoid these problems and charge a mobile phone, headphones or console controller simply by placing it on the surface in question.


A cube that turns air into water


One of the most remarkable inventions at CES in terms of sustainability is an inflatable farm for growing food sustainably in deserts and drought-stricken areas. It is in these challenging places that another of the CTA's award-winning devices can be particularly useful: a device that creates water out of thin airCalled WaterCube 100, it can theoretically produce more than 100 gallons (378 litres) of fresh water a day. That would be enough for a household of four, according to its creators, who don't offer many details on how the technology works, but say that it "mimics nature's process to extract water from the air."


WaterCube 100 is a device designed to generate water from air. Credit: Genesis Systems


A window that generates electricity


From a floor that generates energy from footsteps to autonomous boats controlled by artificial intelligence, those were some of the most innovative green technologies of recent years. At this year's CES event, held between 9 and 12 January in Las Vegas, transparent solar glass called SQPV glass, which can capture light from both sides of the glass, won an award. Its creators claim that in addition to generating electricity from sunlight, it "can also harness energy from invisible light, even in dimly lit indoor settings or on a cloudy day."


A machine that eliminates harmful algae


Harmful algae and cyanobacteria can produce toxins that can make people and animals sick and harm the environment, according to the US Centers for Disease Control and Prevention (CDC). Manual removal of these algae can be costly and carries some risks. The CTA points out that harmful chemicals are sometimes used and that environmentally friendly solutions take too long to take effect. That's where AI ECO ROBOT comes in, an autonomous system that promises to remove these algae and identify potential problems quickly and efficiently.


AI ECO ROBOT removes harmful algae from lakes, rivers and oceans. Credit: Jason Park


A privacy-friendly biometric solution


Facial recognition raises privacy concerns, not least because of the collection and storage of biometric data. The company Ghostpass aims to store biometric information individually on users' smart devices, rather than in bulk in the cloud. "Our solution is to send the biometric data detected by the authentication request to the user's smartphone for authentication. This allows the user to fully own the sovereignty of biometric information," it explains.

These are just some of the most innovative devices for smart cities and smart homes of the 21st century. But there are many more: from a pool-cleaning robot charged by the sun to plug-in smoke detectors, beds that monitor the heart rate and breathing of dogs and cats, or all kinds of smart mirrors. According to the CTA, all these devices share a common goal: "Energy efficiency and automation are leading trends in this sector, and consumers prefer products that save time and money while improving safety and overall well-being."

Tungsteno is a journalism laboratory to scan the essence of innovation.

This website uses its own and third-party cookies to improve the user experience and analyze their behavior in order to improve the service offered.
You can consult additional information about the cookies installed on our Cookies policy.

Cookie Settings

Cookie declaration


These cookies are exempt from compliance with article 22.2 of the LSSI in accordance with the recommendations indicated by the European authority on privacy and cookies. In accordance with the above and although configuration, acceptance or denial is not possible, the editor of this website offers information about them in an exercise of transparency with the user.

  • Name: LFR_Session_STATE_*, Provider: Liferay, Purpose: Manages the session as a registered user , Expiration: Session, Type: HTTP

  • Name: GUEST_LANGUAGE_ID, Provider: Liferay, Purpose: Determines the language with which you access , to show the same in the next session, Expiration: 1 year, Type: HTTP

  • Name: ANONYMOUS_USER_ID, Provider: Liferay, Purpose: Manages the session as an unregistered user , Expiration: 1 year, Type: HTTP

  • Name: COOKIE_SUPPORT, Provider: Liferay, Purpose: Identifies that the use of cookies for the operation of the portal, Expiration: 1 year, Type: HTTP

  • Name: JSessionID, Provider: Liferay, Purpose: Manages login and indicates who is using the site, Expiry: Session, Type: HTTP

  • Name: SACYRGDPR, Supplier: Sacyr, Purpose: Used to manage the cookie policy , Expiration: Session, Type: HTTP