Radio frequency Extraction

Lowe, D.F., Oubre, C.L. and Ward, C.H., Eds., Soil vapor extraction using radio frequency heating, in Resource Manual and Technology Demonstration, Lewis Publishers, Boca Raton, FL, 1999. 

Multi-element determination of dissolved metals at ultratrace level may be performed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). U.S. EPA s Methods 200.8 and 1638 present a methodology for measuring trace elements in waters and wastes by the above technique. Sample is acid digested and the solution is introduced by pneumatic nebulization into a radio-frequency plasma. The elements in the compounds are atomized and ionized. The ions are extracted from the plasma through a differentially pumped vacuum interface and separated by a quadrupole mass spectrometer by their mass to charge ratios. The mass spectrometer must have a resolution capability of 1 amu peak width at 5% peak height. 

Radio frequency heating, 500 Steam stripping, 500 Vacuum extraction, 500 Aeration, 501 Bioremediation, 501 Soil flushing/washing, 502 Surfactant enhancements, 502 Cosolvents, 502 Electrokinetics, 503 Hydraulic and pneumatic fracturing, 503 Treatment walls, 505 Supercritical Water Oxidation, 507 Solid Solution Theory, 202 Solubility products, 48-53 Metal carbonates, 433-434 Metal hydroxides, 429-433 Metal sulfides, 437 Sorption, 167 See Adsorption Specific adsorption, 167 See Chemisorption Stem Layer, 152-154 Sulfate, 261... 

Use of southern pine bark extracts as 50% of the reactive phenolics in endjointing adhesives applied in a honeymoon system has good commercial potential. With proper plant layout and design, the installation, operation, and maintenance of radio-frequency units and their resulting high costs can be avoided. 

In this source the gas inside a tube is ionized by radio-frequency 100 Watts, 10— 100 MHz). A magnetic field concentrates the discharge on the extraction region. The extraction takes place due to a potential difference between the discharge and the beam extractor. The source works very conveniently for gases. For some applications it has the drawback that the energy spread of the ions produced is larger compared with other sources. 

Mass-produced tire-pressure monitoring systems perform these functions by using battery-powered wheel electronics that are able to measure the air pressure and temperature inside the tire. Together with coded information for individual wheel identification and data about battery lifetime, these values are transmitted as radio frequency data messages to an RF antenna mounted in the wheel arch. The data messages are sent independently by all the wheel electronics in a certain time-slot pattern or extracted on demand by using a transmission trigger. A central control unit evaluates the data, identifies the tire, and decides whether the driver should be informed. Each tire is monitored separately. The related air pressure is converted to the standard pressure by means of a temperature characteristic. 

Cochlear implants can be divided into two components the external speech processor and the implanted electrode array and electronics. A diagram of a cochlear implant is shown in Figure 40.1. Sounds recorded by the microphone are sent to the speech processor, which decomposes the incoming waveform and extracts certain cues that allow the speech signal to be represented as a pulse sequence. The information about the pulse sequence is then transmitted transcutaneously to the implanted electronics through a radio-frequency link, where it is decoded and used to specify stimuli that are delivered via the implanted electrode array. 

A quasi-continuous atom laser has been realized in the group of Th.W. Hansch by using a weak radio-frequency field with a small coupling strength as output coupler for the EEC. Atoms could be continuously extracted from the EEC over a time... 

Because fluorescence detection by repeated absorption-emission cycles is not applicable to trapped molecular ions in UHV, that is, in the absence of collisions with a buffer gas [68], different techniques are required for their reliable identification. A commonly used destructive technique for molecular ions is time-of-flight (TOP) mass spectroscopy. We have used a simplified variant in the Ba+ apparatus. The trapped ions are extracted from the trap by reducing the radio-frequency amplitude, in the presence of a finite dc quadrupole potential Vo, which causes the ion trajectories to become unstable (the Mathieu -parameter enters the instability region). Heavy and hot ions escape first. Upon leaving the trap, the ions are guided to and attracted by the cathode of a channel electron multiplier (CEM) and counted. 

FIGURE 18.18 Extraction of ions (of crystal in Figure 18.9d) from the trap by reduction of the radio-frequency drive amplitude. AF+ ions (mass 410 amu) are ejected first. Inset (a), extraction of a different sample of nonlaser-cooled barium and AF+ ions at 300 K the small left-hand peak is due to SC CO impurities. Inset (b), extraction of a laser-cooled Ba" "/AF ion cloud at a temperature of a few hundred mK (fluid state). (From Ostendorf, A. et al., Phys. Rev. Lett, 97, 243005, 2006 Phys. Rev. Lett, 100, 019904(E), 2008. With permission.)... 

In the experiment, illustrated in Figure 17, a 1-keV metastable atomic deuterium beam of density about 10" cm was produced by charge exchange, in cesium vapor, of deuterons extracted from a radio-frequency... 

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