Archive for the ‘energy’ category: Page 22

May 16, 2020

Astrophysicists Warn That Entire Galaxies “Are Being Killed”

Posted by in categories: energy, space

Cosmic Starvation

The first possibility is called ram pressure stripping, a process through which all of the gas that a galaxy would use to form stars is vacuumed away by nearby intergalactic plasma. The other is that the environment inside a galactic cluster simply becomes too hot for cosmic gases to cool and condense into stars, rendering it useless as fuel.

“When you remove the fuel for star formation, you effectively kill the galaxy,” Brown writes, “turning it into a dead object in which no new stars are formed.”

May 16, 2020

A ‘frozen electric-field’ approach to simulate repetitively pulsed nanosecond plasma discharges and ignition of hydrogen–air mixtures

Posted by in categories: chemistry, energy, evolution

High-fidelity modelling of nanosecond repetitively pulsed discharges (NRPDs) is burdened by the multiple time and length scales and large chemistry mechanisms involved, which prohibit detailed analyses and parametric studies. In the present work, we propose a ‘frozen electric-field’ modelling approach to expedite the NRPD simulations without adverse effects on the solution accuracy. First, a burst of nanosecond voltage pulses is simulated self-consistently until the discharge reaches a stationary state. The calculated spatial distributions and temporal evolution of the electric field, electron density and electron energy during the last pulse are then stored in a library and the electrical characteristics of subsequent pulses are frozen at these values. This strategy allows the timestep for numerical integration to be increased by four orders of magnitude (from 10−13 to 10−9 s), thereby significantly improving the computational efficiency of the process. Reduced calculations of a burst of 50 discharge pulses show good agreement with the predictions from a complete plasma model (electrical characteristics calculated during each pulse). The error in species densities is less than 20% at the centre of the discharge volume and about 30% near the boundaries. The deviations in temperature, however, are much lower, at 5% in the entire domain. The model predictions are in excellent agreement with measured ignition delay times and temperatures in H2–air mixtures subject to dielectric barrier NRPD over a pressure range of 54–144 Torr with equivalence ratios of 0.7–1.2. The OH density increases with pressure and triggers low-temperature fuel oxidation, which leads to rapid temperature rise and ignition. The ignition delay decreases by a factor of 2, with an increase in pressure from 54 to 144 Torr. In contrast, an increase in the H2–air equivalence ratio from 0.7 to 1.2 marginally decreases the ignition delay by about 20%. This behaviour is attributed to the insensitivity of OH production rates to the variation in the equivalence ratio.

May 15, 2020

Thermodynamic limits to economic growth on Earth — Can space save us?

Posted by in categories: economics, energy, space

This new paper argues that continued economic growth on Earth will hit a thermodynamic limit within the third millenium, if economic activities and energy consumption cannot be decoupled. The maximum size would be up to 7000 times the current one. An in-space economy would offer a way out.

“Energy Limits to the Gross Domestic Product on Earth” https://arxiv.org/abs/2005.05244

(Image: Wikipedia — https://commons.wikimedia.org/wiki/File:Sky_mile_tower.jpg)

May 15, 2020

A new way to launch rockets without fuel?

Posted by in category: energy

Conventional rockets – with their onboard fuel – are expensive and dangerous. A new “quantized inertia” concept might make rocket launches cheaper and safer. The concept has just received $1.3 million in new funding.

May 13, 2020

“Super steel” breakthrough makes for stronger and tougher alloy

Posted by in categories: energy, materials

It’s a frustrating fact that whenever you try to improve materials like steel, you end up introducing new weaknesses at the same time. It’s a balancing act between different properties. Now, engineers have developed a new type of “super steel” that defies this trade-off, staying strong while still resisting fractures.

For materials like steel, there are three main properties that need to be balanced – strength, toughness and ductility. The first two might sound like the same thing, but there’s an important difference. Strength describes how much of a load a material can take before it deforms or fails, measured in Pascals of pressure. Toughness, meanwhile, measures how much energy it takes to fracture a material.

For reference, glass has relatively high strength but low toughness, so it’s able to support quite a bit of weight but it doesn’t take much energy to break.

May 13, 2020

New device excels at making hydrogen using concentrated sunlight

Posted by in categories: energy, sustainability

System could be scaled-up to supply clean and renewable energy.

May 12, 2020

Woodward effect

Posted by in categories: energy, innovation

Circa 1990 to current o.o

The Woodward effect, also referred to as a Mach effect, is part of a hypothesis proposed by James F. Woodward in 1990.[1] The hypothesis states that transient mass fluctuations arise in any object that absorbs internal energy while undergoing a proper acceleration. Harnessing this effect could generate a reactionless thrust, which Woodward and others claim to measure in various experiments.[2][3]

Hypothetically, the Woodward effect would allow for field propulsion spacecraft engines that would not have to expel matter. Such a proposed engine is sometimes called a Mach effect thruster (MET) or a Mach Effect Gravitation al Assist (MEGA) drive.[4][5] So far, experimental results have not strongly supported this hypothesis,[6] but experimental research on this effect, and its potential applications, continues.[7]

Continue reading “Woodward effect” »

May 9, 2020

In a potential big win for renewable energy, Form Energy gets its first grid-scale battery installation

Posted by in categories: energy, sustainability

Form Energy, which is developing what it calls ultra-low-cost, long-duration energy storage for the grid, has signed a contract with the Minnesota-based Great River Energy to develop a 1 megawatt, 150 megawatt hour pilot project.

The second-largest electric utility in the Minnesota, Great River Energy’s installation in Cambridge, Minn. will be the first commercial deployment of the venture-backed battery technology developer’s long-duration energy storage technology.

From Energy’s battery system is significant for its ability to deliver 1 megawatt of power for 150 hours — a huge leap over the lithium ion batteries currently in use for most grid-scale storage projects. Those battery systems can last for two- to four-hours.

Continue reading “In a potential big win for renewable energy, Form Energy gets its first grid-scale battery installation” »

May 8, 2020

China’s first 100MW molten salt solar plant hits maximum power

Posted by in category: energy

The facility, which serves as a solar thermal power generation demonstration project, has exceeded the amount of power it was originally planned to produce.

May 8, 2020

How Nikola Tesla Planned To Use Earth For Wireless Power Transfer

Posted by in categories: energy, innovation

Serbian-American engineer Nikola Tesla pioneered many modern technologies and made some strange inventions, like the “earthquake-generator.”

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