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Scientists from the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered a possible secret to dramatically boosting the efficiency of perovskite solar cells hidden in the nanoscale peaks and valleys of the crystalline material.

Solar cells made from compounds that have the crystal structure of the mineral perovskite have captured scientists' imaginations. They're inexpensive and easy to fabricate, like organic solar cells. Even more intriguing, the efficiency at which perovskite solar cells convert photons to electricity has increased more rapidly than any other material to date, starting at three percent in 2009 -- when researchers first began exploring the material's photovoltaic capabilities -- to 22 percent today. This is in the ballpark of the efficiency of silicon solar cells.

Especies en todo el mundo van rápidamente extinguiéndose debido a la actividad humana, pero los humanos también están causando una rápida evolución y la aparición de nuevas especies. Un nuevo estudio publicado hoy, resume las causas de la especiación hecha por el hombre y se explica por qué las especies de reciente evolución simplemente no pueden sustituir a las especies silvestres extintas. El estudio fue dirigido por el Centro de Macroecología, Evolución y Clima de la Universidad de Copenhague.

What does the “city of the future” look like?

In an era of rapid technological advancement and increasing urbanization, it’s a fair question. Eighty percent of the U.S. population already lives in large cities* – each with a smartphone, wearable or other device in hand.

As such, city officials are beginning to piece together how those bits of technology can connect with assets like energy meters, garbage cans, street lights, traffic lights, water pipes and more. But, how do we make it all work together? By building a truly smart city.

A truly smart city is one with seamless connectivity that solves local problems and provides its inhabitants with safety, cleanliness and the most efficient ways to get from Point A to Point B. It’s a city that optimizes how we use valuable resources to help improve quality of life, positively impact our planet and open new economic opportunities. A truly smart city provides tremendous opportunities for its citizens and beyond.

Las tuberías que transportan petróleo crudo a puertos en Columbia Británica pueden significar malas noticias para el salmón, según un nuevo estudio liderado por la Universidad de Guelph. La exposición a un producto de arenas bituminosas (betún diluido) que deteriora la capacidad para nadar y cambia las estructuras del corazón de los salmones jóvenes. La investigación será publicada en la revista Environmental Toxicology and Chemistry, y está disponible en línea.

Paris was at the forefront of public bike-sharing schemes, and it now has electric car-sharing schemes and is something of a laboratory for mobility. As of today, motorists with cars built before 1997, and motorcycles built before 2000, will no longer be able to drive them in the city during daylight hours on weekdays.

Paris Mayor Anne Hidalgo says keeping old cars out of the city will help lower pollution levels. But not everyone is happy about it.

Marc Vernhet makes his living driving tourists around Paris in the classic French car known as the Deux Chevaux, or two-horse power. Peugeot Citroen no longer makes the model, but for collectors, it's a nostalgic symbol of the good old days. Vernhet says tourists from all over the world want to ride in them.