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Experimental microbial fuel cells could turn bacteria into batteries that generate electricity from biomass. The key to this technology is the ability of bacteria to transfer electrons to their surroundings—for example, to the anode of a microbial fuel cell. But if the organisms have to be in direct contact with the anode, such devices would have to have extremely large surface areas. Researchers from Aarhus University, in Denmark, report today in the journal Nature that bacteria appear to conduct electricity while separated by several millimeters, at least a thousand times as far apart than previously demonstrated. The naturally occurring electric currents, if confirmed, would allow bacteria spaced at least 12 millimeters apart to communicate electrically. The discovery might lead to new paths to treating infection and a better understanding of microbial ecosystems.

A shielded transformer is a two-winding transformer, usually delta"star connected and serves the following purposes: Voltage transformation from the distribution voltage to the equipment's utilization voltage. Converting a 3-wire input power to a 4-wire output thereby deriving a separate stable neutral for the power supply wiring going to sensitive equipment. Keeping third and its multiple harmonics away from sensitive equipment by allowing their free circulation in the delta winding. Softening of high-frequency noise from the input side by the natural inductance

In 2008 a team of physicists from Argonne National Laboratory, in Illinois, and other institutions stumbled upon an odd phenomenon. They called it superinsulation, because in many ways it was the opposite of superconductivity. Now they’ve worked out the theory behind it, potentially opening the doors to better batteries, supersensitive sensors, and strange new circuits. Superconductors lose all resistance once they fall below a certain temperature. In superinsulators, on the other hand, the resistance to the flow of electricity becomes infinite at very low temperatures, preventing any flow of electric current.

A new form of propulsion that could allow microrobots to explore human bodies has been discovered. The technique would be used to power robots and other devices such as microfluidic pumps from a distance. Finding a propulsion mechanism that works on the microscopic scale is one of the key challenges for developing microrobots. Another is to find a way to supply such a device with energy because there is so little room to carry on-board fuel or batteries. Now a team lead by Orlin Velev at North Carolina State University in Raleigh, US, has found that a simple electronic diode could overcome both these problems. Velev and Vesselin Paunov from the University of Hull, UK, floated a diode in a tank of salt water and zapped the set-up with an alternating electric field.

A new form of propulsion that could allow microrobots to explore human bodies has been discovered. The technique would be used to power robots and other devices such as microfluidic pumps from a distance. Finding a propulsion mechanism that works on the microscopic scale is one of the key challenges for developing microrobots. Another is to find a way to supply such a device with energy because there is so little room to carry on-board fuel or batteries. Now a team lead by Orlin Velev at North Carolina State University in Raleigh, US, has found that a simple electronic diode could overcome both these problems. Velev and Vesselin Paunov from the University of Hull, UK, floated a diode in a tank of salt water and zapped the set-up with an alternating electric field.

In separate keynote addresses in Silicon Valley, two Internet pioneers gave different takes on the future of the network of networks Monday (May 24). Vint Cerf, co-developer of the Net's TCP/IP protocol, shared his thoughts with developers of the smart electric grid, seen as a massive embedded extension to the Internet. Larry Roberts, who helped launch the forerunner of the Internet, explained his ideas for remedying the growing congestion that plagues the Web today. Smart grid developers can learn from the lessons of the Internet, Cerf told attendees at Connectivity Week here. They should follow the model of the Net in creating a layered architecture with plenty of room for flexibility in areas that cannot be anticipated today, he said in a keynote at Connectivity Week.

We’re all familiar with the general idea of a filter: it removes something that we don’t want from something we do want. Coffee filters that pass the liquid coffee but retain the grounds or air filters that pass clean air but trap the dust and other pollutants are two common examples of mechanical filters in everyday life. That same concept can be applied to noisy electrical signals to pass through the “true” signal of interest while blocking the undesirable noise signal. Looking at Figure 2.5c below, imagine for a moment that the signal of interest is in the lower-frequency region and that the noise signal is in the higher-frequency region. Ideally, we’d like to be able to get rid of that high-frequency noise, leaving just the signal component that we want.