Lifeboat Foundation

When optimizing catalysis in the lab, product selectivity and conversion efficiency are primary goals for materials scientists. Efficiency and selectivity are often mutually antagonistic, where high selectivity is accompanied by low efficiency and vice versa. Increasing the temperature can also change the reaction pathway. In a new report, Chao Zhan and a team of scientists in chemistry and chemical engineering at the Xiamen University in China and the University of California, Santa Barbara, U.S., constructed hierarchical plasmonic nanoreactors to show nonconfined thermal fields and electrons. The combined attributes uniquely coexisted in plasmonic nanostructures. The team regulated parallel reaction pathways for propylene partial oxidation and selectively produced acrolein during the experiments to form products that are different from thermal catalysis. The work described a strategy to optimize chemical processes and achieve high yields with high selectivity at lower temperature under visible light illumination. The work is now published on Science Advances.

Catalysts

Ideal catalytic processes can produce desired target products without undesirable side effects under cost-effective conditions, although such conditions are rarely achieved in practice. For instance, high efficiency and high selectivity are antagonistic goals, where a relatively high temperature is often necessary to overcome the large barrier of oxygen activation to achieve high reactant conversion. Increasing the functional temperature can also lead to overoxidized and therefore additional byproducts. As a result, researchers must compromise between selectivity and efficiency. For instance, a given molecule typically requires diverse catalysts to generate different products, where each catalyst has different efficiency and selectivity. To circumvent any limitations, they can use surface plasmons (SPs) to redistribute photons, electrons and heat energy in space and time.

Researchers at the University of Ottawa have debunked the decade-old myth of metals being useless in photonics – the science and technology of light – with their findings, recently published in Nature Communications, expected to lead to many applications in the field of nanophotonics.

“We broke the record for the resonance quality factor (Q-factor) of a periodic array of metal nanoparticles by one order of magnitude compared to previous reports,” said senior author Dr. Ksenia Dolgaleva, Canada Research Chair in Integrated Photonics (Tier 2) and Associate Professor in the School of Electrical Engineering and Computer Science (EECS) at the University of Ottawa.

“It is a well-known fact that metals are very lossy when they interact with light, which means they cause the dissipation of electrical energy. The high losses compromise their use in optics and photonics. We demonstrated ultra-high-Q resonances in a metasurface (an artificially structured surface) comprised of an array of metal nanoparticles embedded inside a flat glass substrate. These resonances can be used for efficient light manipulating and enhanced light-matter interaction, showing metals are useful in photonics.”

Researchers at the University of Ottawa have debunked the decade-old myth of metals being useless in photonics—the science and technology of light—with their findings, recently published in Nature Communications, expected to lead to many applications in the field of nanophotonics.

“We broke the record for the resonance quality factor (Q-factor) of a periodic array of metal nanoparticles by one order of magnitude compared to previous reports,” said senior author Dr. Ksenia Dolgaleva, Canada Research Chair in Integrated Photonics (Tier 2) and Associate Professor in the School of Electrical Engineering and Computer Science (EECS) at the University of Ottawa.

“It is a well-known fact that metals are very lossy when they interact with light, which means they cause the dissipation of electrical energy. The high losses compromise their use in optics and photonics. We demonstrated ultra-high-Q resonances in a metasurface (an artificially structured surface) comprised of an array of metal nanoparticles embedded inside a flat glass substrate. These resonances can be used for efficient light manipulating and enhanced light-matter interaction, showing metals are useful in photonics.”

Microgrids can connect and disconnect from the grid. By operating on normal “blue-sky” operating days as well as during emergencies, microgrids provide uninterrupted power when the grid goes down — and reduce grid constraints and energy costs when grid-connected. Previously the sole domain of military bases and universities, microgrids are growing 15% annually, reaching an $18 billion market in the U.S. by 2022.

For grid resiliency and reliable power supply, there is no better solution than community-scale microgrids that connect critical infrastructure facilities with nearby residential and commercial loads. Funding feasibility studies and audit-grade designs — so that communities have zero-cost but high-quality pathways to constructable projects, as New York State did with the NY Prize initiative — is a proven way to involve communities in their energy planning and engage the private sector in building low-carbon resilient energy systems.

Unpredictability and complexity are quickening, and technology has its place, but not simply as an individual safeguard or false security blanket. Instead, technology should be used to better calculate risk, increase system resilience, improve infrastructure durability and strengthen the bonds between people in a community both during and in between emergencies.

An atmospheric argon discharge plasma was induced by a high-power microwave beam using a 28 GHz gyrotron and investigated at pressures of 40 kPa–100 kPa and Gaussian peak intensities of 0.115 GW/m2…

The bitcoin market now exceeds $1 trillion with its price rising tenfold in a year, but focus is shifting towards the massive power requirements needed to sustain the online currency.

Here are some questions and answers about bitcoin:

‘Skybrators’ generate clean energy without environmental impact of large windfarms, say green pioneers.

In physics, entropy is the process of a system losing energy and dissolving into chaos. This applies to social systems in everyday life, too. Limiting energy loss can make social systems run better.