Fast high-powered

The electronic switching methods used in the early days of the FFC technique look very simple nowadays. They were severely limited by the lack of suitable electronic power devices which would allow fast high-power switching on inductive loads. This problem was not limited to FFC and was eventually overcome by the development of modern power devices which allowed the introduction of switching methods with considerably better performance. 

The principal physical error is probably geometrical. Compared to this, the above assumptions are not unduly restrictive, although extremely fast high-power excursions at low pressures are ruled out by assumptions (2) and (3). Assumption (2) is more nearly fulfilled at high pressures with low liquid heads. Assumption (3) is acceptable in the vapor-film problem even when the radiative flux from the solid surface is appreciable, provided that the liquid (and, of course, vapor) is nearly transparent. 

Precisely controllable rf pulse generation is another essential component of the spectrometer. A short, high power radio frequency pulse, referred to as the B field, is used to simultaneously excite all nuclei at the T,arm or frequencies. The B field should ideally be uniform throughout the sample region and be on the order of 10 ]ls or less for the 90° pulse. The width, in Hertz, of the irradiated spectral window is equal to the reciprocal of the 360° pulse duration. This can be used to determine the limitations of the sweep width (SW) irradiated. For example, with a 90° hard pulse of 5 ]ls, one can observe a 50-kHz window a soft pulse of 50 ms irradiates a 5-Hz window. The primary requirements for rf transmitters are high power, fast switching, sharp pulses, variable power output, and accurate control of the phase. 

Sodium is used as a heat-transfer medium in primary and secondary cooling loops of Hquid-metal fast-breeder power reactors (5,155—157). Low neutron cross section, short half-life of the radioisotopes produced, low corrosiveness, low density, low viscosity, low melting point, high boiling point, high thermal conductivity, and low pressure make sodium systems attractive for this appHcation (40). 

Pulsed methods in ESR, which have by now taken over NMR instrumentation, have required the development of high power amplifiers and fast switches for microwave and higher frequency radiation. 

In summary, the main issues were presented here concerning experimental investigation of fast-electron transport in solids irradiated at ultra-high intensity using high-power, femtosecond laser pulses. A discussion was given on... 

Proton Exchange Membrane Fuel Cells (PEMFCs) are being considered as a potential alternative energy conversion device for mobile power applications. Since the electrolyte of a PEM fuel cell can function at low temperatures (typically at 80 °C), PEMFCs are unique from the other commercially viable types of fuel cells. Moreover, the electrolyte membrane and other cell components can be manufactured very thin, allowing for high power production to be achieved within a small volume of space. Thus, the combination of small size and fast start-up makes PEMFCs an excellent candidate for use in mobile power applications, such as laptop computers, cell phones, and automobiles. 

One of the characteristics of the LSPR biosensor is its generality. This is a powerful attribute for fast, high throughput screening of adsorbates. (Adapted from Haes, 2003)... 

When the spectral width is of hundreds of parts per million, i.e. more than 105 Hz on high field instruments, a very short excitation pulse is needed. Of course, high power is needed to reach the r.f. energy corresponding to a 90° pulse in a short time. To best exploit the short relaxation times, it is often convenient to use a full 90° excitation pulse and to recycle fast, because magnetization equilibrium is reached quickly. With suitable power supplies and purpose-built probes, short H 90° pulses can be achieved (as short as 2 p,s at 800 MHz) [1]. 

There exists a need for high-power pulsed CW radiation sources to enable fast switching times and high repetition rates for electromagnetic resonance experiments. In addition, commercial development of THz sources is needed so that this technology can be made more widely available to the research community. Furthermore, current detectors for THz spectroscopy have high cooling requirements to minimize noise in spectral data further developments are needed to provide inexpensive and user-friendly detector options. 

Response time. When a reactor is kept operating at high power output and the plant electricity is used for operating an electrolysis system, the electricity can be switched in a fraction of a second from the electrolysis plant to the electrical grid. The fast response times enables this system to be used to regulate the electrical grid (see section entitled Economics). 

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