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Archive for the ‘chemistry’ category: Page 248

Jan 31, 2021

GM Pushes Ahead With Hydrogen Fuel Cell Technology For Long Haul Trucks

Posted by in categories: chemistry, particle physics, transportation

Hydrogen. In theory, it’s the perfect fuel. Run it through a fuel cell and you get electricity, water vapor, and heat. Doesn’t get any more Earth friendly than that, does it? There is theory and then there is reality, starting with where one gets the hydrogen in the first place. It is one of the most abundant elements on Earth — every molecule of water has two hydrogen atoms and there is a lot of water in the world.

Then there is the whole universe of hydrocarbons from gasoline to plastics. By definition, there are hydrogen atoms in all of them and that’s the problem. Hydrogen is so reactive it bonds with everything. Getting pure hydrogen means breaking the chemical bonds that bind to other elements. Keeping it sequestered in its pure state is a whole other conundrum.

Assuming all those challenges are overcome, then comes the question of how to distribute it so it can be used to power the fuel cells in vehicles. A DC fast charging installation might cost $300000 but a hydrogen refueling station can cost $3 million. Compressing it, trucking it, and storing it all present additional hurdles to consider.

Jan 28, 2021

Simulating cities under pandemic conditions to make predictions about future outbreaks

Posted by in categories: biotech/medical, chemistry

An international team of researchers has used modeling techniques borrowed from chemistry applications to create a new kind of city simulator. In their paper published in the journal Proceedings of the Royal Society A, the group describes using their models to create simulations of of COVID-19 spread for two real-world cities: Birmingham England and Bogota Columbia.

Jan 27, 2021

Researchers use nanomaterials to make 2-D diamond clusters at room temperature

Posted by in categories: chemistry, nanotechnology

Atomically thin, 2-D hexagonal boron nitride (h-BN) is a promising material whose protean ability to undergo phase transformations to strong, super lightweight, chemically stable, oxidation-resistant films makes them ideal for protective coatings, nanotechnology thermal applications, deep-UV light emitters, and much more.

Jan 26, 2021

Researchers construct molecular nanofibers that are stronger than steel

Posted by in categories: bioengineering, biotech/medical, chemistry, nanotechnology

Self-assembly is ubiquitous in the natural world, serving as a route to form organized structures in every living organism. This phenomenon can be seen, for instance, when two strands of DNA—without any external prodding or guidance—join to form a double helix, or when large numbers of molecules combine to create membranes or other vital cellular structures. Everything goes to its rightful place without an unseen builder having to put all the pieces together, one at a time.

For the past couple of decades, scientists and engineers have been following nature’s lead, designing molecules that assemble themselves in , with the goal of making nanostructures, primarily for such as drug delivery or tissue engineering. “These small-molecule-based materials tend to degrade rather quickly,” explains Julia Ortony, assistant professor in MIT’s Department of Materials Science and Engineering (DMSE), “and they’re chemically unstable, too. The whole structure falls apart when you remove the water, particularly when any kind of external force is applied.”

She and her team, however, have designed a new class of small molecules that spontaneously assemble into nanoribbons with unprecedented strength, retaining their structure outside of water. The results of this multi-year effort, which could inspire a broad range of applications, were described on Jan. 21 in Nature Nanotechnology by Ortony and coauthors.

Jan 25, 2021

Physicists succeed in filming phase transition with extremely high spatial and temporal resolution

Posted by in categories: chemistry, nanotechnology, particle physics

Laser beams can be used to change the properties of materials in an extremely precise way. This principle is already widely used in technologies such as rewritable DVDs. However, the underlying processes generally take place at such unimaginably fast speeds and at such a small scale that they have so far eluded direct observation. Researchers at the University of Göttingen and the Max Planck Institute (MPI) for Biophysical Chemistry in Göttingen have now managed to film, for the first time, the laser transformation of a crystal structure with nanometre resolution and in slow motion in an electron microscope. The results have been published in the journal Science.

The team, which includes Thomas Danz and Professor Claus Ropers, took advantage of an unusual property of a material made up of atomically thin layers of sulfur and tantalum atoms. At , its is distorted into tiny wavelike structures—a “charge-density wave” is formed. At higher temperatures, a phase transition occurs in which the original microscopic waves suddenly disappear. The electrical conductivity also changes drastically, an interesting effect for nano-electronics.

In their experiments, the researchers induced this phase transition with short laser pulses and recorded a film of the charge-density wave reaction. “What we observe is the rapid formation and growth of tiny regions where the material was switched to the next phase,” explains first author Thomas Danz from Göttingen University. “The ultrafast transmission developed in Göttingen offers the highest time resolution for such imaging in the world today.” The special feature of the experiment lies in a newly developed imaging technique, which is particularly sensitive to the specific changes observed in this phase transition. The Göttingen physicists use it to take images that are composed exclusively of electrons that have been scattered by the crystal’s waviness.

Jan 25, 2021

Scientists use a novel ink to 3D print bone with living cells

Posted by in categories: 3D printing, bioprinting, biotech/medical, chemistry

Scientists from UNSW Sydney have developed a ceramic-based ink that may allow surgeons in the future to 3D-print bone parts complete with living cells that could be used to repair damaged bone tissue.

Using a 3D-printer that deploys a special ink made up of calcium phosphate, the scientists developed a new technique, known as ceramic omnidirectional bioprinting in cell-suspensions (COBICS), enabling them to print -like structures that harden in a matter of minutes when placed in water.

While the idea of 3D-printing bone-mimicking structures is not new, this is the first time such material can be created at room temperature—complete with living cells—and without harsh chemicals or radiation, says Dr. Iman Roohani from UNSW’s School of Chemistry.

Jan 24, 2021

The Empowering Neurologist — David Perlmutter M.D., and Dr. David Sinclair

Posted by in categories: biotech/medical, chemistry, genetics, law, life extension, security

Fair to say that we all assume that aging is inevitable. In reality however, there is no biological law that says we must age. Over the years we’ve seen a variety of theories proposed to explain why we age including the accumulation of damage to our DNA, the damaging effects of chemicals called “free radicals, changes in the function of our mitochondria, and so many others.

Our guest today, Dr. David Sinclair, believes that aging is related to a breakdown of information. Specifically, he describes how, with time, our epigenome accumulates changes that have powerful downstream effects on the way our DNA functions. Reducing these changes to the epigenome is achievable and in fact, even taking it further, his research now reveals that the epigenome can be reprogrammed back to a youthful state.

Continue reading “The Empowering Neurologist — David Perlmutter M.D., and Dr. David Sinclair” »

Jan 23, 2021

You Can Actually See the Milky Way’s Wave When You Map Its Stars

Posted by in categories: chemistry, evolution, space

Spiral galaxies are one of the most commonly known types of galaxy. Most people think of them as large round disks, and know that our Milky Way is counted among their number. What most people don’t realize is that many spiral galaxies have a type of warping effect that, when you look at them edge on, can make it seem like they are forming a wave. Now scientists, led by Xinlun Chen at the University of Virginia, have studied millions of stars in the Milky Way and begun to develop a picture of a “wave” passing through our own galaxy.

Since humans are not currently able to view the Milky Way in an edge-on orientation, they must resort to more brute force methods to develop models about the what, if any, wave our galaxy has. Luckily, scientists now have the tools to do so, in the form of the Sloan Digital Sky Survey and ESA’s Gaia satellite.

The method the team used was to try to identify and track the motions of as many stars as possible. To do this, they used the Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, which is part of the SDSS. This preliminary data allowed them to look at both the chemical compositions as well as the motions of hundreds of thousands of stars. While this motion data was helpful in starting to form the picture of the Milky Way’s wave, it was not sufficient to complete it.

Jan 23, 2021

How Explainable Artificial Intelligence Can Help Humans Innovate

Posted by in categories: biological, chemistry, information science, particle physics, robotics/AI, transportation

I like this idea. I don’t want AI to be a black box, I want to know what’s happening and how its doing it.


The field of artificial intelligence has created computers that can drive cars, synthesize chemical compounds, fold proteins, and detect high-energy particles at a superhuman level.

However, these AI algorithms cannot explain the thought processes behind their decisions. A computer that masters protein folding and also tells researchers more about the rules of biology is much more useful than a computer that folds proteins without explanation.

Continue reading “How Explainable Artificial Intelligence Can Help Humans Innovate” »

Jan 21, 2021

Lasers turn pure aluminum … ‘gold’

Posted by in categories: chemistry, physics

The ultimate goal of the Old World alchemist was to turn inexpensive metals into gold. Modern-day physicists at the University of Rochester’s Institute of Optics (Rochester, NY), have turned aluminum and other metals gold—in color if not chemistry. A femtosecond laser processing technique created by professor Chunlei Guo and his assistant Anatoliy Vorobeyv alters the surface properties of aluminum, platinum, titanium, tungsten, silver, and gold to create tints of gold, blue, gray, black, and even multicolored irridescence.