Peak power

In order to achieve a reasonable signal strength from the nonlinear response of approximately one atomic monolayer at an interface, a laser source with high peak power is generally required. Conuuon sources include Q-switched ( 10 ns pulsewidth) and mode-locked ( 100 ps) Nd YAG lasers, and mode-locked ( 10 fs-1 ps) Ti sapphire lasers. Broadly tunable sources have traditionally been based on dye lasers. More recently, optical parametric oscillator/amplifier (OPO/OPA) systems are coming into widespread use for tunable sources of both visible and infrared radiation. 

The so-called peak power delivered by a pulsed laser is often far greater than that for a continuous one. Whereas many substances absorb radiation in the ultraviolet and infrared regions of the electromagnetic spectrum, relatively few substances are colored. Therefore, a laser that emits only visible light will not be as generally useful as one that emits in the ultraviolet or infrared ends of the spectrum. Further, witli a visible-band laser, colored substances absorb more or less energy depending on the color. Thus two identical polymer samples, one dyed red and one blue, would desorb and ionize with very different efficiencies. 

The Nd YAG rod is a few centimetres long and contains 0.5 to 2.0 per cent by weight of Nd. In pulsed operation the peak power of each pulse is sufficiently high for generation of second, third or fourth harmonics at 533 nm, 355 nm and 266 nm, respectively, using suitable crystals. 

The excimer laser radiation is pulsed with a typical maximum rate of about 200 FIz. Peak power of up to 5 MW is high compared with that of a nitrogen laser. 

CW dye lasers are usually pumped wifh an argon ion laser, up to abouf f W of continuous dye laser power being produced, compared wifh abouf f MW peak power which may be produced in a pulsed dye laser. 

The extremely high peak power densities available ia particle beams and lasers can heat the small amounts of matter ia the fuel capsules to the temperatures required for fusion. In order to attain such temperatures, however, the mass of the fuel capsules must be kept quite low. As a result, the capsules are quite small. Typical dimensions are less than 1 mm. Fuel capsules ia reactors could be larger (up to 1 cm) because of the iacreased driver energies available. 

The transversely excited atmospheric-pressure (TEA) laser, inherently a pulsed device rather than a continuous laser, is another common variety of carbon dioxide laser (33,34). Carbon dioxide—TEA lasers are an important class of high-power pulsed lasers. Pulse durations are in the submicrosecond regime peak powers exceed 10 MW. 

Q-switched mode, ie, pulse duration are on the order of a few tens of nanoseconds and peak power in excess of 10 W. 

Blackbody Emittance. Representative blackbody emittance (9,10), calculated as a power spectral density, is shown in Figure 2. The wavelength, X, of peak power density for a blackbody at temperature, T, is given by Wien s displacement law ... 

At least two manufacturers have developed and installed machines rated to produce more than 210 MW of electricity in the simple-cycle mode. In both cases, the machines were designed and manufactured through cooperative ventures between two or more international gas turbine developers. One 50-Hz unit, first installed as a peaking power faciUty in France, is rated for a gross output of 212 MW and a net simple-cycle efficiency of 34.2% for natural-gas firing. When integrated into an enhanced three-pressure, combined-cycle with reheat, net plant efficiencies in excess of 54% reportedly can be achieved. 

The Combined (Brayton-Rankine) Cycle The 1990s has seen the rebirth of the combined cycle, the combination of gas turbine technologies with the steam turbine. This has been a major shift for the utility industry, which was heavily steam-tnrbine-oriented with the use of the gas turbine for peaking power. In this combined cycle, the hot gases from the turbine exhaust are used in a heat recoveiy steam generator or in some cases in a snpplementaiy fired boiler to produce superheated steam. 

What happens if the expander were operating at peak power so that the exeess power supplied to the generator is represented by line B1 Assume afterburning oeeurs to eause a temperature rise. In the events that follow, there will be variations deteetable in the blower horsepower requirements, but they will be small eompared to the others that oeeur. If the unit was in lined-out operation before the afterburning oeeurred, the operators will be reluetant to disturb the regenerator-reaetor balanee. 

Nakhamkin, M. Increasing Gas Turbine or Combined Cycle Power Production with Compressed Air to Meet Peak Power Demands, ASME Paper No. 2000-GT-0596. 

The life span of a batteiy is also dependent on the power needs of a product. Some batteries produce a lot of power for a relatively short time before fully discharging, while others are designed to provide less peak power but more sustained power for a very low drain rate. Other important variables aftccting batteiy lifespan are the design and efficiency of the device being used and the conditions of use. In particular, exposing a batteiy to excessive heat can dramatically curtail the length of a battery s life. 

Though sodium-sulfur batteries have been under development for many years, major problems still exists with material stability. It is likely that the first commercial uses of this batteiy will not be for electric vehicles. Sodium-sulfur storage batteries may be more well-suited for hybrid electric vehicles or as part of a distributed energy resources system to provide power ill remote areas or to help meet municipal peak power requirements. 

Some conseivation measures do not easily fit into the form of an initial investment followed by a stream of energy savings because there will be other costs and benefits occurring during the measure s operating life. Furthermore, it is difficult to incorporate peak power benefits into the CCE approach. In these situations, a more precise analysis will be necessary. However, the CCE and supply cuive approaches provide first-order identifications of cost-effective conseivation, those... 

Ozone levels and peak power for Southern California Edison versus 4 P.M. temperature in Los Angeles as a predictor of smog. 

Energy, 02one Benefits, and Avoided Peak Power of Cooler Roofs, Pavements, and Trees in Los Angeles Basin... 

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