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Archive for the ‘quantum physics’ category: Page 645

Feb 6, 2019

Quantum dots that produce white light could be the light bulb’s successor

Posted by in categories: energy, quantum physics

Circa 2005


Until 1993 LEDs could only produce red, green and yellow light. But then Nichia Chemical of Japan figured out how to produce blue LEDs. By combining blue LEDs with red and green LEDs – or adding a yellow phosphor to blue LEDs – manufacturers were able create white light, which opened up a number of new applications. However, these LEDs tend to produce white light with a cool, bluish tinge.

The white-light quantum dots, by contrast, produce a smoother distribution of wavelengths in the visible spectrum with a slightly warmer, slightly more yellow tint, reports Michael Bowers, the graduate student who made the quantum dots and discovered their unusual property. As a result, the light produced by the quantum dots looks more nearly like the “full spectrum” reading lights now on the market which produce a light spectrum closer to that of sunlight than normal fluorescent tubes or light bulbs. Of course, quantum dots, like white LEDs, have the advantage of not giving off large amounts of invisible infrared radiation unlike the light bulb. This invisible radiation produces large amounts of heat and largely accounts for the light bulb’s low energy efficiency.

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Feb 6, 2019

Quantum dot white LEDs achieve record efficiency

Posted by in categories: nanotechnology, particle physics, quantum physics, sustainability

Circa 2018


Researchers have demonstrated nanomaterial-based white-light-emitting diodes (LEDs) that exhibit a record luminous efficiency of 105 lumens per watt. Luminous efficiency is a measure of how well a light source uses power to generate light. With further development, the new LEDs could reach efficiencies over 200 lumens per watt, making them a promising energy-efficient lighting source for homes, offices and televisions.

“Efficient LEDs have strong potential for saving energy and protecting the environment,” said research leader Sedat Nizamoglu, Koç University, Turkey. “Replacing conventional lighting sources with LEDs with an of 200 lumens per watt would decrease the global electricity consumed for lighting by more than half. That reduction is equal to the electricity created by 230 typical 500-megawatt coal plants and would reduce greenhouse gas emissions by 200 million tons.”

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Feb 6, 2019

Graphene quantum dots sensitized C-ZnO nanotaper photoanodes for solar cells application

Posted by in categories: quantum physics, solar power, sustainability

In a paper to be published in the forthcoming issue in NANO, researchers from the National Institute of Technology, India, have synthesized blue-green-orange photoemissive sulfur and nitrogen co-doped graphene quantum dots (SNGQDs) using hydrothermal method. These GQDs showed strong UV-visible photoabsorption and excitation dependent photoemission which have low-cost, eco-friendly solar cell application.

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Feb 6, 2019

New research signals big future for quantum radar

Posted by in categories: biotech/medical, nanotechnology, quantum physics

A prototype quantum radar that has the potential to detect objects which are invisible to conventional systems has been developed by an international research team led by a quantum information scientist at the University of York.

The new breed of radar is a hybrid system that uses correlation between microwave and optical beams to detect objects of low reflectivity such as cancer cells or aircraft with a stealth capability. Because the quantum radar operates at much lower energies than conventional systems, it has the long-term potential for a range of applications in biomedicine including non-invasive NMR scans.

The research team led by Dr Stefano Pirandola, of the University’s Department of Computer Science and the York Centre for Quantum Technologies, found that a special converter — a double-cavity device that couples the microwave beam to an optical beam using a nano-mechanical oscillator — was the key to the new system.

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Feb 6, 2019

China’s latest quantum radar could help detect stealth planes, missiles

Posted by in categories: military, quantum physics

Circa 2018


China’s quantum radar makes more progress, and China plans to put it high up in the stratosphere, to spy on ballistic missiles and stealth aircraft.

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Feb 6, 2019

The Race to Develop the World’s Best Quantum Tech

Posted by in categories: economics, quantum physics, security

The United States and China both see quantum technologies as key to national security and economic progress.

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Feb 6, 2019

Brewing nanotechnology from tea

Posted by in categories: biotech/medical, nanotechnology, quantum physics, solar power, sustainability

Quantum dots, which have potential uses in medical imaging and solar cells, could be made with help from the polyphenols found in tea leaves.

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Feb 4, 2019

Quantum Physics May Be Even Spookier Than You Think

Posted by in categories: particle physics, quantum physics

What actually occurs in a superposition—the strange condition in which entities seem to be in two or more places or states at the same? This is the root question in quantum mechanics, and the answer was unknown until now. In a new research paper, a joint team of researchers from Israel and Japan, has described a novel experiment that could finally shed light on the true nature of this puzzling phenomenon.

The researchers estimate that their experiment, that can be carried out within a few months, could possibly allow scientists a sneak peek at where an object like a particle of light i.e. a photon will actually be when it is positioned in a superposition. And as per their predictions, the answer can be even stranger and more baffling than “two places at once.”

The characteristic occurrence of a superposition involves firing photons at two parallel slits into a barrier. One fundamental aspect of quantum mechanics is that the tiny particles can behave like waves, so that those passing through one slit “interfere” with those passing through the other. These wavy ripples either boost or cancel one another to create a new characteristic pattern on a detector screen. The oddest fact is that this interference occurs even if only a single particle is fired at a time. The particle seems to somehow pass through both slits simultaneously and displays interference with itself. This is a true superposition.

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Feb 3, 2019

The Search for New Physics & CERN’s FCC Future Circular Collider

Posted by in categories: astronomy, engineering, environmental, ethics, existential risks, particle physics, physics, quantum physics, science

It is a few years since I posted here on Lifeboat Foundation blogs, but with the news breaking recently of CERN’s plans to build the FCC [1], a new high energy collider to dwarf the groundbreaking engineering triumph that is the LHC, I feel obliged to write a few words.

The goal of the FCC is to greatly push the energy and intensity frontiers of particle colliders, with the aim of reaching collision energies of 100 TeV, in the search for new physics [2]. Below linked is a technical note I wrote & distributed last year on 100 TeV collisions (at the time referencing the proposed China supercollider [3][4]), highlighting the weakness of the White Dwarf safety argument at these energy levels, and a call for a more detailed study of the Neutron star safety argument, if to be relied on as a solitary astrophysical assurance. The argument applies equally to the FCC of course:

The Next Great Supercollider — Beyond the LHC : https://environmental-safety.webs.com/TechnicalNote-EnvSA03.pdf

The LSAG, and others including myself, have already written on the topic of astrophysical assurances at length before. The impact of CR on Neutron stars is the most compelling of those assurances with respect to new higher energy colliders (other analogies such as White Dwarf capture based assurances don’t hold up quite as well at higher energy levels). CERN will undoubtedly publish a new paper on such astrophysical assurances as part of the FCC development process, though would one anticipate it sooner rather than later, to lay to rest concerns of outsider-debate incubating to a larger audience?

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Feb 2, 2019

Researchers want to revolutionise AI

Posted by in categories: quantum physics, robotics/AI

Today, I talk not just about Exponential Technologies but also about Exponential Combinations, by combining Quantum Computing with Neural Networks we’d revolutionise both.

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