Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: energy – Page 79

Under the limitation of current density, micro-LED is difficult to achieve watts level optical power, which is not suitable for long-distance and underwater optical communication that requires high-power optical transmitter devices. Therefore, how to improve the communication performance of conventional-size LED is also a key issue at present.

The authors of an article published in Opto-Electronic Science studied a wavelength division multiplexing visible light communication system based on multi-color LED. The system uses a Si substrate GaN-based LED with a 3D structured quantum well. In the active layer of this LED, there is a three-dimensional structure (“V” shaped pit, or V-pit) with a hexagonal profile, opening towards the P-type GaN layer.

With the large-scale commercial use of 5G, global academia and industry have started research on the next-generation mobile communication technology (6G).

However, the existing RF spectrum resources are seriously depleted to meet the spectrum demand of 6G for ultra-high speed and ultra-large capacity. This severe challenge stimulates researchers to focus on higher frequency bands such as terahertz, infrared and . Among them, visible light communication utilizes the ultra-wide spectrum from 400THz to 800THz, which has the merits of no licensing, high secrecy, environmental-friendly, and no electromagnetic radiation.

Continue reading “Engineers develop enhanced GaN-based LED array visible light communication system” | >

A research team led by Prof. Yan Lifeng from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) has designed a water-based nanomicellar electrolyte by using methylurea (Mu). The results were published in the Journal of the American Chemical Society.

Aqueous zinc ion batteries (AZIBs) are competitive candidates for clean energy storage, but they are severely limited by the irreversible electrochemical reaction of the zinc anode. Therefore, it is a crucial issue to explore how to regulate the electrochemical performance of AZIBs through electrolyte design optimization.

In this paper, the researchers proposed a unique design of nanomicellar electrolyte, which comprises ZnSO4, MnSO4 and a high concentration of Mu molecules through a self-assembly strategy, where the aqueous-solvent environment is partitioned into hydrophilic and hydrophobic regions, and cations and anions are encapsulated into nanodomains.

Read more | >

Sunlight is an inexhaustible source of energy, and utilizing sunlight to generate electricity is one of the cornerstones of renewable energy. More than 40% of the sunlight that falls on Earth is in the infrared, visible and ultraviolet spectra; however, current solar technology utilizes primarily visible and ultraviolet rays. Technology to utilize the full spectrum of solar radiation—called all-solar utilization—is still in its infancy.

A team of researchers from Hokkaido University, led by Assistant Professor Melbert Jeem and Professor Seiichi Watanabe at the Faculty of Engineering, have synthesized tungstic acid–based materials doped with copper that exhibited all-solar utilization. Their findings are published in the journal Advanced Materials.

“Currently, the near-and mid-infrared spectra of solar radiation, ranging from 800 nm to 2,500 nm, is not utilized for energy generation,” explains Jeem. “Tungstic acid is a candidate for developing nanomaterials that can potentially utilize this spectrum, as it possesses a crystal structure with defects that absorb these wavelengths.”

Read more | >

Kevin Slagle, Quantum 7, 1113 (2023). Although tensor networks are powerful tools for simulating low-dimensional quantum physics, tensor network algorithms are very computationally costly in higher spatial dimensions. We introduce $\textit{quantum gauge networks}$: a different kind of tensor network ansatz for which the computation cost of simulations does not explicitly increase for larger spatial dimensions. We take inspiration from the gauge picture of quantum dynamics, which consists of a local wavefunction for each patch of space, with neighboring patches related by unitary connections. A quantum gauge network (QGN) has a similar structure, except the Hilbert space dimensions of the local wavefunctions and connections are truncated. We describe how a QGN can be obtained from a generic wavefunction or matrix product state (MPS). All $2k$-point correlation functions of any wavefunction for $M$ many operators can be encoded exactly by a QGN with bond dimension $O(M^k)$. In comparison, for just $k=1$, an exponentially larger bond dimension of $2^{M/6}$ is generically required for an MPS of qubits. We provide a simple QGN algorithm for approximate simulations of quantum dynamics in any spatial dimension. The approximate dynamics can achieve exact energy conservation for time-independent Hamiltonians, and spatial symmetries can also be maintained exactly. We benchmark the algorithm by simulating the quantum quench of fermionic Hamiltonians in up to three spatial dimensions.

Read more | >

At a somewhat small and unassuming airport in Maribor, Slovenia, German hydrogen propulsion startup H2FLY has quietly been building up to a major milestone in zero-emission aviation over the summer. And all the hard work has come to fruition, with the successful completion of the world’s first crewed liquid hydrogen-powered flights.

Before any aviation history enthusiast out there goes “but what about the Tupolev Tu-155?” — yes, the Soviets did try out liquid hydrogen as fuel 35 years ago, but only for one of the three engines. In contrast, H2FLY’s HY4 has now operated using only liquid hydrogen (as opposed to the gaseous kind) as fuel, relying solely on the hydrogen fuel-cell powertrain for the entire flight.

Read more | >

Vertical farming saves water, land, and energy — and it could be how we grow food on Mars.

Subscribe here: http://freeth.ink/youtube-subscribe-verticalfarming.

Vertical farming is a type of indoor farming where crops are grown in stacked layers, rather than spread out across large plots of land. These farms offer many benefits over traditional ones, including the prospect of better access to healthy foods in underserved communities.

Because vertical farms use LED lighting, their output isn’t subject to the natural elements that typically affect plant production such as adverse weather, insects, and seasons.

Continue reading “Vertical farms could take over the world | Hard Reset by Freethink” | >

Using a ballpoint pen filled with specially formulated inks, scientists have designed LEDs that can be drawn on everyday materials.

Even in our digital age, ballpoint pens are an irreplaceable tool for writing down flashes of inspiration or signing legally binding documents. The ink flowing through these everyday objects has always been a passive absorber of light, but Junyi Zhao from Washington University in St. Louis and colleagues have now changed that [1]. The team has designed a ballpoint pen that writes with ink that produces light as a light emitting diode (LED).

LEDs are used in everything from TV screens to lightbulbs. They are often made using highly tunable semiconducting materials called halide perovskites. However, these devices have traditionally been time and energy intensive to fabricate, and they do not easily adhere to nonuniform substrates, such as fabric and plastic.

Read more | >

A team of researchers, led by a University of Hawai’i (UH) at Manoa planetary scientist, discovered that high energy electrons in Earth’s plasma sheet are contributing to weathering processes on the Moon’s surface and, importantly, the electrons may have aided the formation of water on the lunar surface. The study was published today in Nature Astronomy.

Understanding the concentrations and distributions of water on the Moon is critical to understanding its formation and evolution, and to providing water resources for future human exploration. The new discovery may also help explain the origin of the water ice previously discovered in the lunar permanently shaded regions.

Due to Earth’s magnetism, there is a force field surrounding the planet, referred to as the magnetosphere, that protects Earth from space weathering and damaging radiation from the Sun. Solar wind pushes the magnetosphere and reshapes it, making a long tail on the night side. The plasma sheet within this magnetotail is a region consisting of high energy electrons and ions that may be sourced from Earth and the solar wind.

Read more | >