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Archive for the ‘engineering’ category: Page 2

Feb 11, 2024

A scalable photoelectrochemical system for green hydrogen production

Posted by in categories: chemistry, engineering, solar power, sustainability

If realized using solar energy or other renewable energy, water splitting could be a promising way of sustainably producing hydrogen (H2) on a large-scale. Most photoelectrochemical water splitting systems proposed so far, however, have been found to be either inefficient, unstable, or difficult to implement on a large-scale.

Researchers at Ulsan National Institute of Science and Technology (UNIST) recently set out to develop a scalable and efficient photoelectrochemical (PEC) system to produce green hydrogen. Their proposed system, outlined in Nature Energy, is based on an innovative formamidinium lead triiodide (FAPbI3) perovskite-based photoanode, encapsulated by an Ni foil/NiFeOOH electrocatalyst.

“Our group has thoroughly studied the challenges associated with practical solar hydrogen production,” Jae Sung Lee, Professor of Energy & Chemical Engineering at UNIST and co-author of the paper, told Tech Xplore. “As summarized in our most recent review paper, minimum 10% of solar-to-hydrogen (STH) efficiency is required to develop viable practical PEC system, for which selecting an efficient material is the first criteria.”

Feb 8, 2024

New techniques for making qubits out of erbium

Posted by in categories: computing, engineering, particle physics, quantum physics

Qubits are the building block for quantum technology, and finding or building qubits that are stable and easily manipulated is one of the central goals of quantum technology research. Scientists have found that an atom of erbium—a rare-earth metal sometimes used in lasers or to color glass—can be a very effective qubit.

To make qubits, erbium atoms are placed in “host materials,” where the erbium atoms replace some of the material’s original atoms. Two research groups—one at quantum startup memQ, a Chicago Quantum Exchange corporate partner, and one at the US Department of Energy’s Argonne National Laboratory, a CQE member—have used different host materials for erbium to advance , demonstrating the versatility of this kind of qubit and highlighting the importance of materials science to quantum computing and quantum communication.

The two projects address challenges that quantum computing researchers have been trying to solve: engineering multi-qubit devices and extending the amount of time qubits can hold information.

Feb 7, 2024

Nanomedicine advancement shows potential for personalized point-of-care therapeutics

Posted by in categories: biotech/medical, engineering

Stefan Wilhelm, an associate professor in the Stephenson School of Biomedical Engineering at the University of Oklahoma, and several students in his Biomedical Nano-Engineering Lab have recently published an article in the journal Nano Letters (“Toward the Scalable, Rapid, Reproducible, and Cost-Effective Synthesis of Personalized Nanomedicines at the Point of Care”) that outlines their recent important nanomedicine advancement.

The group examined how to create tools that produce nanomedicines, such as vaccine formulations, directly at the point of care. In doing so, the large centralized facilities, shipping challenges, and extreme cold storage challenges faced during the COVID-19 pandemic would no longer limit vaccine distribution.

Wilhelm, with student researchers such as Hamilton Young, a senior biomedical engineering student, and Yuxin He, a biomedical engineering graduate research assistant, used 3D printer parts to mix fluid streams together containing the building blocks of nanomedicines and their payloads in a T-mixer format.

Feb 6, 2024

Solar geoengineering could start soon if it starts small

Posted by in categories: climatology, engineering, particle physics

It’s possible to start a subscale deployment in just a few years. The climate effects would be tiny, but the geopolitical impact could be significant.

Feb 6, 2024

Scientists Have Solved the 141-Year-Old ‘Reverse Sprinkler’ Problem

Posted by in categories: engineering, neuroscience, physics

This brain-teaser has baffled physicists since 1883. Thanks to some innovative engineering, it finally makes sense.

Feb 5, 2024

Joint research team develops edge-to-edge assembly technique for 2D nanosheets

Posted by in categories: chemistry, engineering

A collaborative research team has fabricated a soccer ball-shaped construction using edge-to-edge assembly of 2D semiconductor materials. The research has been featured on the cover of the online edition of the Angewandte Chemie International Edition journal.

The research team, led by Professor In Su Lee and Ph.D. candidate Sun Woo Jang from the Department of Chemistry at Pohang University of Science and Technology (POSTECH), along with Professor Kwangjin An from the Department of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST), successfully controlled the interaction between the edges of 2D-silica nanosheets (2D-SiNS) to create a soccer ball-like structure.

The planar structure of 2D nanosheets exhibit unique mechanical and , making them versatile in semiconductor devices, catalysts, sensors, and many other sectors. The strong attraction of intermolecular forces (van der Waals) between sheets typically results in a structure where faces are in direct contact, compromising mechanical stability for catalytic functionality.

Feb 5, 2024

Visualizing multiple sclerosis with a new MRI procedure

Posted by in categories: biotech/medical, engineering, neuroscience

Multiple sclerosis (MS) is a neurological disease that usually leads to permanent disabilities. It affects about 2.9 million people worldwide, and about 15,000 in Switzerland alone. One key feature of the disease is that it causes the patient’s own immune system to attack and destroy the myelin sheaths in the central nervous system.

These protective sheaths insulate the nerve fibers, much like the plastic coating around a copper wire. Myelin sheaths ensure that electrical impulses travel quickly and efficiently from nerve cell to nerve cell. If they are damaged or become thinner, this can lead to irreversible visual, speech and coordination disorders.

So far, however, it hasn’t been possible to visualize the myelin sheaths well enough to reliably diagnose and treat MS. Now researchers at ETH Zurich, led by Markus Weiger and Emily Baadsvik from the Institute for Biomedical Engineering, have developed a new magnetic resonance imaging (MRI) procedure that maps the condition of the myelin sheaths more accurately than was previously possible. The researchers successfully tested the procedure on healthy people for the first time.

Feb 1, 2024

AI-Powered Proof Generator Helps Debug Software

Posted by in categories: biotech/medical, cybercrime/malcode, engineering, mathematics

Not all software is perfect—many apps, programs, and websites are released despite bugs. But the software behind critical systems like cryptographic protocols, medical devices, and space shuttles must be error-free, and ensuring the absence of bugs requires going beyond code reviews and testing. It requires formal verification.

Formal verification involves writing a mathematical proof of your code and is “one of the hardest but also most powerful ways of making sure your code is correct,” says Yuriy Brun, a professorat the University of Massachusetts Amherst.

To make formal verification easier, Brun and his colleagues devised a new AI-powered method called Baldur to automatically generate proofs. The accompanying paper, presented in December 2023 at the ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering in San Francisco, won a Distinguished Paper award. The team includes Emily First, who completed the study as part of her doctoral dissertation at UMass Amherst; Markus Rabe, a former researcher at Google, where the study was conducted; and Talia Ringer, an assistant professor at the University of Illinois Urbana-Champaign.

Jan 31, 2024

In novel quantum computer design, qubits use magnets to selectively communicate

Posted by in categories: computing, engineering, quantum physics

When you push a button to open a garage door, it doesn’t open every garage door in the neighborhood. That’s because the opener and the door are communicating using a specific microwave frequency, a frequency no other nearby door is using.

Researchers from the U.S. Department of Energy’s (DOE) Argonne National Laboratory, the University of Chicago, the University of Iowa and Tohoku University in Japan have begun to develop devices that could use the same principles — sending signals through magnets instead of through the air — to connect individual qubits across a chip, as reported in a new paper published in the Proceedings of the National Academy of Sciences.

“This is a proof of concept, at room temperature, of a scalable, robust quantum technology that uses conventional materials,” said David Awschalom, the Liew Family professor in molecular engineering and physics at the University of Chicago’s Pritzker School of Molecular Engineering; the director of the Chicago Quantum Exchange; the director of Q-NEXT, a DOE National Quantum Information Science Research Center hosted at Argonne; and the principal investigator of the project. “The beauty of this experiment is in its simplicity and its use of well-established technology to engineer and ultimately entangle quantum devices.

Jan 31, 2024

A method for examining ensemble averaging forms during the transition to turbulence in HED systems for application to RANS models

Posted by in categories: engineering, physics, space, supercomputing

Simulating KH-, RT-, or RM-driven mixing using direct numerical simulations (DNS) can be prohibitively expensive because all the spatial and temporal scales have to be resolved, making approaches such as Reynolds-averaged Navier–Stokes (RANS) often the more favorable engineering option for applications like ICF. To this day, no DNS has been performed for ICF even on the largest supercomputers, as the resolution requirements are too stringent.8 However, RANS approaches also face their own challenges: RANS is based on the Reynolds decomposition of a flow where mean quantities are intended to represent an average over an ensemble of realizations, which is often replaced by a spatial average due to the scarcity of ensemble datasets. Replacing ensemble averages by space averages may be appropriate for flows that are in homogenous-, isotropic-, and fully developed turbulent states in which spatial, temporal, and ensemble averaging are often equivalent. However, most HED hydrodynamic experiments involve transitional periods in which the flow is neither homogeneous nor isotropic nor fully developed but may contain large-scale unsteady dynamics; thus, the equivalency of averaging can no longer be assumed. Yet, RANS models often still require to be initialized in such states of turbulence, and knowing how and when to initialize them in a transitional state is, therefore, challenging and is still poorly understood.

The goal of this paper is to develop a strategy allowing the initialization of a RANS model to describe an unsteady transitional RM-induced flow. We seek to examine how ensemble-averaged quantities evolve during the transition to turbulence based on some of the first ensemble experiments repeated under HED conditions. Our strategy involves using 3D high-resolution implicit large eddy simulations (ILES) to supplement the experiments and both initialize and validate the RANS model. We use the Besnard–Harlow–Rauenzahn (BHR) model,9–12 specifically designed to predict variable-density turbulent physics involved in flows like RM. Previous studies have considered different ways of initializing the BHR model.

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