Energy & Green Tech

Operator: Impact from release of Fukushima water minimal

The operator of the tsunami-wrecked Fukushima nuclear power plant said Wednesday that a data simulation of its planned release of treated radioactive water into the sea suggests it would have an extremely small impact on ...

Energy & Green Tech

New insight could lead to better silicon solar panels

Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) and Colorado School of Mines are applying a new technique to identify defects in silicon solar cells that cause a drop in efficiency. ...

Energy & Green Tech

Stable solar cells from perovskite

Perovskite is a promising material. It captures the sun's rays and efficiently converts them into solar energy. It is also much cheaper than the current generation of silicon solar cells. But why are the Dutch rooftops not ...

Energy & Green Tech

Solid-state batteries line up for better performance

Solid-state batteries pack a lot of energy into a small space, but their electrodes are not good at keeping in touch with their electrolytes. Liquid electrolytes reach every nook and cranny of an electrode to spark energy, ...

Energy & Green Tech

Weakness is strength for this low-temperature battery

Nanoengineers at the University of California San Diego have discovered new fundamental insights for developing lithium metal batteries that perform well at ultra-low temperatures; mainly, that the weaker the electrolyte ...

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Perturbation theory (quantum mechanics)

In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak disturbance to the system. If the disturbance is not too large, the various physical quantities associated with the perturbed system (e.g. its energy levels and eigenstates) can, from considerations of continuity, be expressed as 'corrections' to those of the simple system. These corrections, being 'small' compared to the size of the quantities themselves, can be calculated using approximate methods such as asymptotic series. We can therefore study the complicated system based on our knowledge of the simpler one.

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