From animal welfare to environmental sustainability, there are plenty of reasons people choose to avoid eating meat derived from animals. Many current meat alternatives rely on plant-based proteins, most often from soy and wheat, which can readily mimic the texture and nutritional value of the real thing. While 3D printing has already been tested for meat alternatives, none of the current formulations include proteins from these particular plants. So, Songbai Liu and Shanshan Wang wanted to figure out an approach to making a meat “dough” with soy and wheat protein that could be produced effectively with a 3D printer.

The researchers tested soy and wheat proteins in formulations containing several other ingredients using a 3D printer. They evaluated their concoctions based on the accuracy with which the dough could be laid down by the printer and how well it held its form. They also examined its texture and microstructure. The experiments revealed the importance of several additional ingredients, including the emulsifier Tween-80 and sodium alginate to control the texture. Heat-sensitive cocoa butter turned out to be a particularly important ingredient, making the dough more fluid at warm temperatures for printing, but then hardening afterward at room temperature, allowing the dough to retain its printed shape. One drawback, however, is that people who cannot eat wheat gluten or soy because of allergies or celiac disease would not be able to partake of the new alternatives. To address this issue, the researchers attempted to replace the soy protein with that from peas, but the resulting dough was too soft for printing. Even so, these experiments have identified a new strategy for formulating meat alternatives using this versatile technology, according to the researchers.

The authors acknowledge funding from the National Key Research and Development Program, the Zhejiang Public Welfare Technology Research Program, the Qinghai Science and Technology Program and the Foundation of Fuli Institute of Food Science at Zhejiang University.

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Materials provided by American Chemical Society. Note: Content may be edited for style and length.

Most current drowsiness detection systems use an exterior, forward-looking camera to monitor lane position or sudden, exaggerated corrections. Others use an interior camera to check a driver’s face or eyes for signs of nodding off. Camera-based systems, while useful, have drawbacks. For example, an exterior camera could be blocked by mud, and an interior camera could be less effective at night. Scientists have previously explored using piezoelectric sensors — self-powered materials that accumulate an electrical charge in response to pressure — for monitoring a driver’s posture, which changes when a person falls asleep, has a sudden health emergency or is intoxicated. However, existing piezoelectric sensors cannot withstand high temperatures, a requirement for electrical and electronic equipment in vehicles. Toshimi Nagase and colleagues wanted to develop flexible, heat-resistant piezoelectric sheet sensors that could be embedded in a vehicle’s seat to monitor the driver’s posture.

The researchers prepared zinc oxide-based films directly on a polyimide surface and then screen-printed a silver paste on both sides to obtain a piezoelectric sheet. They connected a coaxial cable to detect changes in electrical charge with pressure and then folded the sheet in half around the cable. The sensor sheet resisted heating up to 250 F, with no changes in its properties. After showing that the sensor could discriminate changes in mechanical load, the team placed a sensor in the back of a chair. By detecting a seated person’s slight body movements, the sensor allowed the researchers to calculate the person’s respiration and pulse rates. Two other sensors attached to the seat of a chair could sense when a person leaned left or right with their upper body, which could indicate drowsiness.

The researchers say that in the future, a monitoring system based on the sensors might detect changes in vital signs or body posture, triggering a self-driving car to find a safe location and then stop. The vehicle could also contact emergency healthcare providers, depending on the situation. To get to that point, the next step is to test the piezoelectric sensors in a car, where vehicle motions and vibrations will contribute to background noise in the measurements, the team says.

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Materials provided by American Chemical Society. Note: Content may be edited for style and length.

In 2013, a nearly complete leather scale armor was found in the tomb of an approx. 30-year-old male near the modern-day city of Turfan in Northwest China. This unprecedented find, which survived the millennia thanks to the area’s extremely arid climate, provided the international team led by Patrick Wertmann from the Institute of Asian and Oriental Studies of the University of Zurich with new insights on the spread of military technology during the first millennium BCE.

Scale armors protect the vital organs of fighters like an extra layer of skin without restricting their mobility. The armors were made of small shield-shaped plates arranged in horizontal rows and sewn onto a backing. Due to the costly materials and laborious manufacturing process, armors were very precious, and wearing them was considered a privilege of the elite. It was rare for them to be buried with the owner. However, the emergence of powerful states with large armies in the ancient world led to the development of less precious but nevertheless effective armors made of leather, bronze or iron for ordinary soldiers.

Standard military equipment for horsemen

The researchers used radiocarbon dating to determine the age of the armor to between 786 and 543 BCE. It was originally made of about 5,444 smaller scales and 140 larger scales, which together with leather laces and lining weighed between 4 and 5kg. The armor resembles a waistcoat that protects the front of the torso, hips, the sides and the lower back of the body. It can be put on quickly without the help of another person and fits people of different statures.

“The armor was professionally produced in large numbers,” says Patrick Wertmann. With the increasing use of chariots in Middle Eastern warfare, a special armor for horsemen was developed from the 9th century BCE. These armors later became part of the standardized equipment of military forces of the Neo-Assyrian Empire, which extended from parts of present-day Iraq to Iran, Syria, Turkey and Egypt.

Two armors, distinct units

While there is no direct parallel to the 2,700-year-old armor in the whole of Northwest China, there are some stylistic and functional similarities to a second contemporary armor of unknown origin held by the Metropolitan Museum of Art in New York (the Met). It is possible that the two armors were intended as outfits for distinct units of the same army, i.e. the Yanghai armor for cavalry and the armor in the Met for infantry.

It is unclear whether the Yanghai armor belonged to a foreign soldier working for the Assyrian forces who brought it back home with him, or whether the armor was captured from someone else who had been to the region. “Even though we can’t trace the exact path of the scale armor from Assyria to Northwest China, the find is one of the rare actual proofs of West-East technology transfer across the Eurasian continent during the early first millennium BCE,” says Wertmann.

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The group headed by Hongyu Yu – first at RUB, later at the Canadian Geological Survey of Canada – and RUB Professor Rebecca Harrington describes the results in the journal Nature Communications, published online on 25 November 2021.

Several theories on the origins of earthquakes

To date, researchers have explained the occurrence of earthquakes in the hydraulic-fracturing process with two processes. The first says that the fluid pumped into the rock generates a pressure increase substantial enough to generate a new network of fractures in the subsurface rocks near the well. As a result, the pressure increase can be large enough to unclamp existing faults and trigger an earthquake. According to the second process, the fluid pressure increase from injection in the subsurface also exerts elastic stress changes on the surrounding rocks that can be transmitted over longer distances. If the stress changes occur in rocks where faults exist, it can also lead to changes that cause the fault to slip and cause an earthquake.

Recently, numerical models and lab analyses have predicted a process on faults near injection wells that has been observed elsewhere on tectonic faults. The process, termed aseismic slip, starts out as slow slip that does not release any seismic energy. The slow slip can also cause a stress change on nearby faults that causes them slip rapidly and lead to an earthquake. The lack of seismic energy from aseismic slip and the size of the faults involved make it difficult to observe in nature. Researchers have therefore not yet been able to document aseismic slip broadly with any association to induced earthquakes. The work of the current study, provides indirect evidence of aseismic loading, and a transition from aseismic to seismic slip.

Modifying the hydraulic fracturing process

The German-Canadian research team interpret the recently discovered slow earthquakes as an intermediate form of conventional earthquake and aseismic slip – and thus as indirect evidence that aseismic slip can also occur in the vicinity of wells. The researchers therefore dubbed the events hybrid-frequency waveform earthquakes (EHW).

“If we understand at which point the subsurface reacts to the hydraulic-fracturing process with movements that don’t result in an earthquake and, consequently, cause no damage to the surface, ideally we could use that information to adjust the injection procedure accordingly,” as Rebecca Harrington, Head of the Hydrogeomechanics Group at RUB, describes one implication of the study.

Not all quakes spread at the same rate

“We’d assumed that induced earthquakes behave like most other earthquakes and have roughly the same rupture speed of two to three kilometres per second,” explains Rebecca Harrington. But that doesn’t always seem to be the case. While the shaking from a conventional earthquake of magnitude 1.5 in the researchers’ data set had died down after about seven seconds, an EHW earthquake of the same magnitude continued to shake for more than ten seconds.

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Materials provided by Ruhr-University Bochum. Note: Content may be edited for style and length.