Ramabhadran R.,General Electric |
She X.,General Electric |
Levy Y.,Efficient Power Conversion |
Glaser J.,GE Lighting |
And 2 more authors.
2015 IEEE Energy Conversion Congress and Exposition, ECCE 2015 | Year: 2015
In this paper, we present the design and fabrication of a high density laptop adapter with a Clamped Series Resonant Converter (CSRC), as a possible alternative to traditional Flyback converters for power adapters in portable electronics. The target is to design for universal AC input up to a power of 100 W with power density of 6-7 W/in3. The converter is frequency controlled, and all switches exhibit Zero-Current Switching (ZCS). In this paper, we show that by utilizing the magnetizing inductance, the converter can be tuned for Zero Voltage Switching (ZVS), and by adding a switched capacitor circuit to extend the input voltage range, we can realize a very compact design that is suitable for power adapters with or without power factor correction. Low transformer stresses compared to Flyback type designs enable high densities, even with a resonant magnetic. Prototype test results with a 45 W laptop adapter are presented. Our initial testing with diode rectification indicated very good efficiency. Versions with synchronous rectification promise higher efficiencies by at least 1%, which will be ideal for energy saving low power devices. © 2015 IEEE. Source
The City of San Diego is lit with something quite a bit smarter than the average city. In a pilot program with GE Lighting, San Diego is slowly replacing its street lights with a system of sensor-driven LED lights that also serve as a base layer for smart city services. The lights can dim or strengthen based on information the sensors pick up — such as people walking on the street or twilight progressing into nightfall. And they can be paired with other smart city services. Just what those are is part of the pilot but they could be identifying heavy traffic or, sensing smoke, alerting 911. Public safety is a key likely benefit. Just switching out 10 percent of San Diego's lighting resulted in saving $250,000. Imagine the savings once most of the city is lit up with these smart LED bulbs. David Graham, COO of neighborhood services for the city of San Diego, and Kathy Sterio, CMO of GE Lighting, explain in this VERGE video what the pilot is all about. The equipment is the hardware of LED lights, which are semiconductor driven, plus sensors plus software. The combination could allow street lights to be "the analytical brains of the city," Sterio said. But privacy concerns ought not to be an issue, Sterio and Graham said, because the sensors pick up group motions or data trends, not individual behavior.
News Article | March 24, 2014
Happy Monday, dear readers. Here are your morning links. JPMorgan Chase's CEO of investment banking for China is leaving. Fang Fang, 48, told the bank he wanted to retire, which is understandable. U.S. authorities are investigating whether JPMorgan hired the children of China's elite so that their powerful relatives in government would steer business to the bank, and Fang's e-mails discussing the bank's hiring practices are among those under scrutiny. But it's still too early to know where this probe is headed. Because if federal prosecutors decide that nepotism in China is illegal, imagine what might happen if they ever investigated what goes on every day in Washington and New York. The Financial Times has a good editorial explaining why: "Take, for example, the mechanism for resolving a bank in trouble. In theory, this process should happen over a weekend, so as to avoid the risks of market turmoil and bank runs. The final arrangement, however, will involve multiple panels and more than 100 decision makers. National governments, which have the least incentive to shut down a bank in trouble since this might provoke a political backlash, will retain a say." Plus, individual countries will still shoulder the costs of rescuing or shutting down their own failing banks. And the common resolution fund, at a mere 55 billion euros, is a joke. The fund won't even be that large for another eight years. What happens when prices for new apartments in China drop? The people who agreed to pay the old (higher) prices, but haven't received their apartments yet, get upset. From the Wall Street Journal: "Groups of angry homeowners put up banners and demanded their money back after Hong Kong-listed property developer Wharf Ltd. cut prices on new homes in an eastern Chinese city, in the latest sign of stress in the nation's property market. Around 20 homeowners picketed outside a property showroom in Changzhou Saturday, demanding to meet executives of the developer. They said they wanted their money back after prices at the project, called Phoenix Lake Garden, were cut by as much as 16 percent, according to the protesters." His bet against Herbalife Ltd. is close to breaking even, thanks in part to the recently disclosed Federal Trade Commission investigation of the company. " Impactful information is not always insider, and insider information is not always impactful!" That's the title of Aswath Damodaran's latest post at Musings on Markets, and I like his explanation. He also doesn't think much of Eric Schneiderman's latest campaign against stuff that the New York attorney general has deemed Insider Trading 2.0, whatever that's supposed to mean: "While Mr. Schneiderman's motives may be noble (or at least they sound good), I don't think that he has thought through either the principles behind this new doctrine or the potential consequences." And finally, here are some cool pictures of dogs . The photographer's name is Elke Vogelsang. And her stuff is wonderful. This column does not necessarily reflect the opinion of Bloomberg View's editorial board or Bloomberg LP, its owners and investors.
Tallosy S.P.,University of Szeged |
Janovak L.,University of Szeged |
Menesi J.,University of Szeged |
Nagy E.,University of Szeged |
And 5 more authors.
Environmental Science and Pollution Research | Year: 2014
Nanosilver-modified TiO2 and ZnO photocatalysts were studied against methicillin-resistant Staphylococcus aureus on the surface and against naturally occurring airborne microorganisms. The photocatalysts/polymer nanohybrid films were prepared by spray coating technique on the surface of glass plates and on the inner surface of the reactive light source. The photoreactive surfaces were activated with visible light emitting LED light at λ = 405 nm. The optical properties of the prepared photocatalyst/polymer nanohybrid films were characterized by diffuse reflectance measurements. The photocatalytic properties were verified with the degradation of ethanol by gas chromatography measurements. The destruction of the bacterial cell wall component was examined with transmission electron microscope. The antibacterial effect of the photocatalyst/polymer nanohybrid films was tested with different methods and with the associated standard ISO 27447:2009. With the photoreactive coatings, an extensive disinfectant film was developed and successfully prepared. The cell wall component of S. aureus was degraded after 1 h of illumination. The antibacterial effect of the nanohybrid films has been proven by measuring the decrease of the number of methicillin-resistant S. aureus on the surface and in the air as the function of illumination time. The photocatalyst/polymer nanohybrid films could inactivate 99.9 % of the investigated bacteria on different thin films after 2 h of illumination with visible light source. The reactive light source with the inner-coated photocatalyst could kill 96 % of naturally occurring airborne microorganisms after 48 h of visible light illumination in indoor air sample. The TEM results and the microbiological measurements were completed with toxicity tests carried out with Vibrio fischeri bioluminescence bacterium. © 2014, Springer-Verlag Berlin Heidelberg. Source
Somogyvari Z.,GE Lighting |
Almosdi P.,GE Lighting
Journal of Light and Visual Environment | Year: 2013
Steady-state glow discharge operation has been studied on model fluorescent lamps equipped with bare tungsten electrode filaments. Energy transfer mechanisms were measured by electrode temperatures as a function of electric driving parameters and fill gas pressure. The measurements were evaluated and discussed by application of plasma models of the cathode dark space region. Source