Discover Top Posts Tagged with #materials sciences

The oldest known operation was a leg amputation performed 31,000 years ago—and it worked!

A young boy, likely 8-12 years old, had a catastrophic leg injury that destroyed his lower leg. It came about either due to a crushing injury like a rock collapse, or he had suffered a severe animal bite, leaving the boy with a deep wound that damaged blood vessels beyond repair. The surgeons removed the leg because it was the only way to save the child's life—and save they did. The boy survived miraculously almost until the average life expectancy, which at that time was only 25-35 years. The boy lived another 6-9 years without his leg & died around 20. This operation took place in Liang Tebo Cave, East Kalimantan, Borneo, Indonesia.

The surgeons used sharpened stone blades (likely razor-sharp flaked stone made from silica rock). These could be as sharp as modern surgical steel when freshly honed. They may have given the boy plant-based antiseptics as well as herbal sedatives during the operation. Keep in mind that such endeavors have never been attempted before & the next surgery would not occur for another 24,000 years: a trepanation (skull surgery). The Borneo amputation is so advanced that it doesn't fit the timeline—it's a medical outlier thousands of years ahead of its time. Remember, this is still the era commoners call the "Caveman" era. We call it the Pleistocene Era, which began 2.6 million years ago and ended 11,700 years ago. They were cave dwellers; societies were hunter-gatherers; they used stone tools; they still had Ice Age megafauna, & early Homo sapiens coexisted alongside Neanderthals.

The Borneo child's surgery was so sophisticated that it rewrote the history of medicine. It shows that cavemen had medical knowledge; they understood healing; they cared for injured children for years, & they performed surgery long before agriculture, cities, or writing. They had a wide cornucopia of herbal plants & potions to choose from because Borneo's rainforest is one of the most chemically rich ecosystems on Earth. Even today, Indigenous groups still use many of those same plants they used back then.

For example, turmeric is a natural antiseptic and is a strong anti-inflammatory, contains curcumin, & is used today on wounds. Ginger has pain-reducing & antimicrobial properties; cinnamon bark contains cinnamaldehyde, a powerful antimicrobial. Tea tree oil (Melaleuca species), its oils & leaves kill bacteria & fungi. Neem species have antibacterial & antifungal properties. Pain control was essential, so they likely used kava kava, which is a mild sedative that reduces anxiety & numbs pain. Betel leaf has psychoactive compounds & is widely chewed today in India & Indonesia, used as a wrapper for paan—a combination of areca nut, slaked lime, & catechu—a reddish-brown paste extracted from the acacia tree. (It's catechu, which stains teeth a horrid reddish-brown.)

They may have used kratom, native to Southeast Asia, which has opioid-like pain relief properties & acts as a mild sedative. It was very available in the region. They perhaps also used clove, which is rich in eugenol, a natural anesthetic & is still used today in dentistry. The child's bone showed no infection; there was full healing of the tibia/fistula. The leg was removed at the mid-tibia, roughly 12-14 inches (30-35 cm) below the knee. These tropical rainforest plants are extremely potent and necessary for a person undergoing amputation.

Acting as the main interface between the internal and the external world, the skin is the largest and most important organ of the human body

Acting as the main interface between the internal and the external world, the skin is the largest and most important organ of the human body. It is frequently exposed to many types of physical injuries or wounds, including cuts, scrapes, scratches, infections, and ulcers. Unfortunately, as one ages, the skin becomes more frail and less capable of healing itself without help. With many countries experiencing a rapid rise in the aging population, the demand for treating such skin wounds has created a greater need for accessible and effective wound care products.

#Science #Biochemistry #Materials Sciences #Health #Hydrogel #Japan

The Beverly Hillbillies, but make it battery-grade.

An Ontario, Canada, real estate developer & entrepreneur bought an abandoned Union Carbide site in Welland, Ontario, & accidentally discovered a multi-billion dollar synthetic graphite stockpile. Excavations revealed 340,000 tonnes of high-grade synthetic graphite. At market prices up to USD 20,000/tonne, the stockpile could be worth $6.8 billion. This is important for a couple of reasons. The first is that China controls over 90% of the world's anode-grade graphite supply. China's export restrictions have made Western automakers desperate for non-Chinese sources. Charest's find is one of the largest known synthetic graphite stockpiles in North America, already validated for battery use. As such, demand is projected to double from 5.4M tonnes (2025) to 10.1M tonnes in 2030.

You might think batteries only require lithium; however, that is only the cathode (where electrons arrive) part of the battery. The anode (where electrons leave), the other half of the battery, is almost entirely graphite. Every EV battery uses 10x more graphite than lithium by weight. The graphite must be ultra-pure, spheroidized & micronized—a specialty process China dominates. That's why Charest's discovery is so important because it's not just graphite he found but synthetic-grade graphite, the hardest type to source. Union Carbide is historically known for extremely high-purity synthetic carbon. Graphite is almost entirely pure carbon. This is the writing source of pencils, not lead. When you write, you're literally shearing off tiny sheets of carbon that stick to the paper. Graphite is useful in batteries because it is open enough for lithium ions to slip between the layers & stable enough to survive thousands of charge cycles.

#science #geology #mineralogy #materials chemistry #carbon fiber #electrochemistry #battery #materials sciences

By shining a strong beam of light through two chemical compounds, scientists discovered a unique new state of matter made of particles calle

Physicists have discovered an exotic new state of matter that takes the form of a highly ordered crystal of subatomic particles. The new state of matter, called a "bosonic correlated insulator," could lead to the discovery of many new types of exotic materials made from condensed matter, according to the researchers, who detailed their results in a study published May 11 in the journal Science. Subatomic particles can be separated into two categories: fermions and bosons. The primary differences between the two are how they spin and how they interact with each other. Fermions, such as electrons and protons, are often thought of as the building blocks of matter because they make up atoms, and are characterized by their half-integer spin. Two identical fermions cannot occupy the same space at the same time. "Bosons can occupy the same energy level; fermions don't like to stay together," study lead author Chenhao Jin, a condensed-matter physicist at the University of California, Santa Barbara, said in a statement. "Together, these behaviors construct the universe as we know it." But there is a case in which two fermions can become a boson: If a negatively charged electron is secured to a positively charged "hole" in a different fermion, it forms a bosonic particle known as an "exciton." To see how excitons interact with one another, the researchers layered a lattice of tungsten disulfide atop a similar lattice of tungsten diselenide in an overlapping pattern called a moiré. Then, they shined a strong beam of light through the lattices — a method known as "pump-probe spectroscopy." These conditions pushed the excitons together until they were so densely packed that they could no longer move, creating a new symmetrical crystalline state with a neutral charge — a bosonic correlated insulator.

#science #stem #physics #excitons #materials sciences

Electrolysis is a process that uses electricity to create hydrogen and oxygen molecules from water. The use of proton exchange membrane (PEM

Electrolysis is a process that uses electricity to create hydrogen and oxygen molecules from water. The use of proton exchange membrane (PEM) and renewable energy for water electrolysis is widely regarded as a sustainable method for hydrogen production. However, a challenge in advancing PEM water electrolysis technology is the lack of efficient, low-cost, and stable catalysts for oxygen evolution reaction (OER) in acidic solutions during PEM water electrolysis.

#Science #Chemistry #Materials Sciences #Electrolysis #Energy #Hydrogen Energy

"We think that this has really important implications, not just in terms of making tough materials that don't fracture, but also materials that would go into robotics and aerospace and armored suits and things like this,"

University of California, Berkeley, chemists have created a new type of material from millions of identical, interlocking molecules, that for the first time allows the synthesis of extensive 2D or 3D structures that are flexible, strong and resilient, like the chain mail that protected medieval knights.

The material, called an infinite catenane, can be synthesized in a single chemical step.

French chemist Jean-Pierre Sauvage shared the 2016 Nobel Prize in Chemistry for synthesizing the first catenane—two linked rings. These structures served as the foundation for making molecular structures capable of moving, which are often referred to as molecular machines.

#Science #stem #chemistry #materials sciences #technology

The world's most doomed arts & crafts project.

I'm referring to the theory of what would happen if someone decided to throw a paper airplane from space. It's an interesting theory, but it never actually occurred. When first thrown, the plane wouldn't "fly"; it would just float. There's no air in space, no swooping, no turning. If thrown from the ISS for example, which is 250 mi (402 km) above Earth, it would simply drift forward at the same speed the station is moving, 17,500 mph (28,163 km/h). It would just orbit Earth like any other satellite. Even a 0.01-oz (0.3 g) paper plane becomes a bullet-like projectile at orbital speed. It would orbit Earth for months, slowly losing speed due to extremely thin air. Re-entry begins around 50-75 miles up (80-120 km/h). At this point the plane would still be moving at Mach 25 (17,500 mph/28,000 km/h). At this point air molecules slam into it so hard that they heat it to 3,000-4,000°F (1,650-2,200°C). Since paper ignites at 451°F (233°C), it would long have been vaporized.

#science #aerospace engineering #atmospheric science #thermodynamics #materials sciences #physics #earth science

The California chemical that almost went boom & the smelly problem that accidentally led to Plexiglas & modern cataract eye surgery.

It is no longer a problem because firefighters sprayed huge amounts of water for hours on the outside of the storage tanks to keep the metal cool. They injected a chemical foam inside the tanks to smother vapors. They used drones to find the hot spots. The chemical stored inside is methyl methacrylate (MMA). The tanks were stored at GNK Aerospace in Garden Grove, & authorities had ordered mass evacuations in the area as a precaution. As a result of the incident, multiple class-action lawsuits were launched. The suit accused GKN of failing to maintain the MMA tanks safely, creating a public nuisance & operating ultrahazardous activities near homes. So far, the lawsuits have not been settled.

It's not actually MMA itself that is dangerous. MMA is a liquid monomer used to make acrylic plastics, but when MMA forms long chains (called polymerization), it becomes exothermic, & if the heat can't escape, you get bulging tank walls, valve failures, flying metal pieces, a fireball, burning MMA on the ground, & potential boiling liquid expanding vapor explosions, shortened to BLEVE. The big tank holding 34,000 gallons (129,000 L) can explode, releasing harmful vapors, causing fire, blast damage to homes & residents nearby, & potential secondary releases of burning or decomposing chemicals. The tank is only 35 mi (56 km) away from Los Angeles. Believe it or not, the chemicals involved here (methylmethyl acrylate & its polymer polymethylmethacrylate) lead to a fascinating story that I'll tell you about.

It all began with a terrible smell with pits full of, believe it or not, dog poop. In Stuttgart, Germany, in 1904, a young German chemist, Dr. Arthur Röhn, worked near old-style tanneries. Back then, tanners softened animal hides in pits full of dog poop. The smell was unbearable. So he invented a synthetic tanning chemical he named Oriphon. This became the 1st successful synthetic leather-processing product. He became very wealthy, which launched his career. Arthur partnered up with an Austrian businessman, Otto Haas. Their company became a giant in acrylic chemistry. Rohm discovered a way to form long chains of the monomer MMA forming PMMA discovering that when they linked together, they would form a clear, hard, shatter-resistant plastic we know as Plexiglass (Perspex) in Europe. This was the first truly clear, strong, glass-like plastic. From this material, Arthur created the first eyeglasses made of plastic. Then, a Canadian chemist, William Chalmers at my alma mater, McGill University, figured out a way to scale it up. It was affordable, consistent, strong, & ready for industrial use.

PMAA soon became a wartime material, & it was used as a clear, protective canopy over pilots' heads. The Germans used it as well, but it was of a poorer quality, so it cracked in cold weather & yellowed faster. Allied Plexiglass was simply better, & pilots found that even if it would shatter after crashes & some splinters went into their eyes, doctors noted their eyes tolerated PMMA extremely well & they did not have severe immune reactions. This observation changed medicine. A British eye surgeon, Sir Harold Ridley, realized that if the eye accepts Plexiglass, why not make a lens out of it? And in 1949, he implanted the 1st successful artificial lens made of Plexiglass (Perspex). This was the birth of cataract surgery.

Before this, cataract patients were left with thick "Coke-bottle" glasses because the natural lens had to be removed. Ridley's PMAA lens changed everything. Later, surgeons refined the technique. Dr. Cornelius Binkhorse (Netherlands) & Dr. Marvin Kwitco (Montreal) developed ways to anchor the lens, shape the lens, & implant it safely, combining PMAA with silicone. These improvements made cataract surgery safer, faster (now it could be done within 2 hours on an outpatient basis), more predictable & more widely available. Modern Plexiglass lenses are flexible, foldable, crystal-clear & inserted through tiny incisions (0.08-0.12 in/2-3 mm), requiring no stitching.

Even MMA has important uses such as road markings (yes, the paint on highways), adhesives & glues for cars, airplanes, boats & for construction, & dental materials such as dentures & crowns, orthopedic surgeons use MMA as "bone cement" in hip & knee replacements & for waterproof coatings. One of the most well-known tourist destinations in Japan is the Hippopo Papa Cafe, where patrons sit on a Plexiglass toilet seat encircled by three sides of a massive Plexiglass aquarium while responding to nature's call amid tropical fish. PMAA (Plexiglass/Perspex) is widely used for aquariums. When you fly, you're looking out of Plexiglass windows. It's also used for taillights, instrument panels for cars, & motorcycle windshields. Architects use them for skylights & building windows. They're used for display cases in museums & in home decor for shelves, artificial chairs, tables & lighting fixtures, eyeglasses & artificial teeth. In hospitals, PMAA is used for incubators, surgical instrument housing & protective shields.

Finally, it solved the problem of penile injury for 2-3-year-old boys undergoing toilet training. There were 9,000 reported cases of penile injury from dropping heavy toilet seats made of solid wood, porcelain-coated wood, or heavy composite materials on their penises. Physicians became rightfully concerned. The solution? Sloped lids, slow-drop mechanisms using Plexiglass. The lid is super-light & takes 3-5 seconds to close instead of 1/2 second. The rock group even wrote about it on the Styx album "The Serpent is Rising," a short, humorous hidden track referred to as "Plexiglass Toilet Seat," kind of a musical joke about a man who gets stuck to a Plexiglass toilet seat. It's one of the strangest—and most practical—uses of acrylic plastic. My little nephew's mom cannot be more overjoyed.