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Category: chemistry – Page 213

Wooden objects are usually made by sawing, carving, bending or pressing. That’s so old school! Today, scientists will describe how flat wooden shapes extruded by a 3D printer can be programmed to self-morph into complex 3D shapes. In the future, this technique could be used to make furniture or other wooden products that could be shipped flat to a destination and then dried to form the desired final shape.

The researchers will present their results at the fall meeting of the American Chemical Society (ACS).

In nature, plants and some animals can alter their own shapes or textures. Even after a tree is cut down, its wood can change shape as it dries. It shrinks unevenly and warps because of variations in fiber orientation within the wood. “Warping can be an obstacle,” says Doron Kam, a graduate student who is presenting the work at the meeting, “but we thought we could try to understand this phenomenon and harness it into a desirable morphing.”

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In a significant development, Massachusetts Institute of Technology (MIT) engineers have developed a new category of wireless wearable skin-like sensors for health monitoring that doesn’t require batteries or an internal processor.

The team’s sensor design is a form of electronic skin, or “e-skin” — a flexible, semiconducting film that conforms to the skin like electronic Scotch tape, according to a press release published by MIT.

“If there is any change in the pulse, or chemicals in sweat, or even ultraviolet exposure to skin, all of this activity can change the pattern of surface acoustic waves on the gallium nitride film,” said Yeongin Kim, study’s first author, and a former MIT postdoc scholar.

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Near-term quantum computers, quantum computers developed today or in the near future, could help to tackle some problems more effectively than classical computers. One potential application for these computers could be in physics, chemistry and materials science, to perform quantum simulations and determine the ground states of quantum systems.

Some quantum computers developed over the past few years have proved to be fairly effective at running . However, near-term quantum computing approaches are still limited by existing hardware components and by the adverse effects of background noise.

Researchers at 1QB Information Technologies (1QBit), University of Waterloo and the Perimeter Institute for Theoretical Physics have recently developed neural , a new strategy that could improve ground state estimates attained using quantum simulations. This strategy, introduced in a paper published in Nature Machine Intelligence, is based on machine-learning algorithms.

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I believe that these microbes are not just simple organisms but are some sorta biological singularity seeds that activate over millions of years developing life slowly and may be exterrestial in origin.

Researchers from Hokkaido University in Japan have found new evidence that the chemical components necessary to build DNA may have been carried to Earth by carbonaceous meteorites, some of the earliest matter in the solar system, as they report in a study published Tuesday in Nature Communications. Although these kinds of materials make up about 75 percent of all asteroids, they rarely fall to Earth, limiting how often scientists can study them. Yet they are troves of information: Scrutinizing these space rocks can tell stories about unique cosmic locations. Their contents may also help reveal the ancient chemical reactions that made our world a living planet.

Specifically, several meteorites have been found to contain nucleobases. These chemicals, called the building blocks of life, make up the nucleic acids inside DNA and RNA. Of the five major nucleobases, previous meteorite studies detected only three of them, named adenine, guanine, and uracil. But the present research proves for the first time that two more—cytosine and thymine—can exist within space rocks.

“The detection of all primary DNA and RNA nucleobases in meteorites indicates that these molecules have been supplied to the early Earth before the onset of life,” says Yasuhiro Oba, lead author of the study and an associate professor at Hokkaido University. ” In other words, we got information about the inventory of organic molecules related to DNA and RNA before any life arose on the Earth.” One of the oldest specimens in the study clocks in at about 4.6 billion years old, which is even older than the solar system.

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A novel method for measuring nanoparticle size could have applications in industry and basic materials science research.

Nanoparticles are present in everything from paints to pharmaceutical products. While nanoparticles have many important characteristics, such as molecular composition and shape, it is their size that determines many chemical and physical properties. A new technique relying on an optical vortex—a laser beam whose wave fronts twist around a dark central region—allows researchers to characterize nanoparticle size rapidly and continuously [1]. This light-based size probe might one day find applications in numerous industrial settings and aid fundamental materials science research.

It is difficult to precisely synthesize nanoparticles with the desired dimensions, so manufacturers must often validate that their nanoparticles have the right size to comply with regulations and to ensure product quality. There are many ways of determining nanoparticle size, but one popular approach, dynamic light scattering (DLS), is based on measurements of Brownian motion, the random particle movement caused by jostling from the surrounding liquid medium. In DLS, the Brownian motion is determined by measuring fluctuations in laser light scattering from the nanoparticles. In general, the faster the Brownian motion, the smaller the particles. But current techniques are generally not capable of characterizing the largest particles and measuring them continuously.

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Capacitors are energy storage devices—consisting of two electrodes and an electrolyte—that are capable of rapid charging and discharging because of charge adsorption and desorption properties at the electrode-electrolyte interface. Because capacitors’ energy storage does not involve chemical reactions, their storage capacity is lower than that of lithium-ion batteries, but they are useful for power leveling for renewable energy that requires repeated charging at high currents, regenerative braking energy for trains and electric or hybrid cars, as well as instantaneous voltage drop compensation devices that prevent equipment failure due to lightning strikes. They are also expected to be used to store energy for wearable devices in the near future.

Most capacitors use a liquid electrolyte with a low boiling point, which can only be used at temperatures below 80℃. Ceramic capacitors that use solid inorganic materials as a dielectric can be used at temperatures above 80℃, but their is much lower than liquid electrolyte capacitors, which limits their use to electronic circuits.

To increase the energy storage of capacitors, it is necessary to have a large contact area at the interface between the electrode and the electrolyte. Making a large contact area is difficult using ; so, the creation of a capacitor with high storage capacity that can also operate at high temperatures has been desired for a long time.

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The Brain Chemical Involved in Consciousness

So how do we help these people? The brain is more than just a congregation of different areas. Brain cells also rely on a number of chemicals to communicate with other cells, enabling a number of brain functions. Before our study, there was already some evidence that dopamine, well known for its role in reward, also plays a role in disorders of consciousness.

For example, one study showed that dopamine release in the brain is impaired in minimally conscious patients. Moreover, a number of small-scale studies have shown that patients’ consciousness can improve by giving them drugs that act through dopamine.

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Flexible electronics have enabled the design of sensors, actuators, microfluidics and electronics on flexible, conformal and/or stretchable sublayers for wearable, implantable or ingestible applications. However, these devices have very different mechanical and biological properties when compared to human tissue and thus cannot be integrated with the human body.

A team of researchers at Texas A&M University has developed a new class of biomaterial inks that mimic native characteristics of highly conductive , much like skin, which are essential for the ink to be used in 3D printing.

This biomaterial ink leverages a new class of 2D nanomaterials known as molybdenum disulfide (MoS2). The thin-layered structure of MoS2 contains defect centers to make it chemically active and, combined with modified gelatin to obtain a flexible hydrogel, comparable to the structure of Jell-O.

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