Radio-frequency waves

A unique process for chemical stabili2ation of a ceUular elastomer upon extmsion has been shown for ethylene—propylene mbber the expanded mbber obtained by extmsion is exposed to high energy radiation to cross-link or vulcani2e the mbber and give dimensional stabUity (9). EPDM is also made continuously through extmsion and a combination of hot air and microwaves or radio frequency waves which both activate the blow and accelerate the cure. 

RF (radio frequency) welding Utilizes specific bands of radio frequency waves which are directed through specially constructed tooling to form localized melting/joining of certain dielectric thermoplastic materials. Can be used to form hermetic seals. Also known as high frequency or dielectric welding. 

The various forms of spectroscopy find widespread application in kinetic studies. They are usually well suited for application to in situ studies of the characteristics of the reaction mixture. The absorption by a reacting system of electromagnetic radiation (light, microwaves, radio-frequency waves, etc.) is a highly specific property... 

Bj) G. Bekefi S.C. Brown, Emission of Radio-Frequency Waves from Plasma , AmerJPhys 29, 404-28(1961)... 

Spectroscopy involves the study of the interactions of electromagnetic radiation with matter. In the case of liquids, radiation of a wide range of frequencies, and thus energies, has been used, all the way from radio-frequency waves to X-rays. Experiments involving neutrons, which are associated with very short wavelengths, are also important. In the spectroscopic experiment the incident radiation may be either absorbed or scattered and the experimental information is obtained by examining the intensity and direction of the radiation after it has passed through the sample. 

At this point it is necessary to relate the relaxation time for the chemical process to the spin-spin relaxation process which is always present when the system absorbs energy from the radio frequency wave. Both processes lead to broadening of the NMR absorption peak. If T, is the total relaxation time for process i, it may be estimated from T2 and x,- using the relationship... 

Like NMR, NQR spectra are detected by flipping nuclei using MHz-range radio-frequency waves NQR frequencies can readily be measured to within a few kHz. Since NQR frequencies are extremeJy sensitive to small changes in the electronic environment of quadrupolar nuclei, they are... 

The use of microwaves is essentially a method of using electromagnetic radiation to provide the energy needed for a chemical reaction. Radio-frequency waves, which are electromagnetic radiation at lower frequencies, have been used for industrial heating for a few decades. The most common commercial radio fre-... 

Press Curing - Press curing includes the molding of articles by compression, transfer, or injection methods. Blocked-in articles which are cured directly between press platens also come under this classification, as well as unblocked slabs. The heat source is generally saturated steam. Electrically heated platens are also used in some installations. Radio frequency waves have been suggested as a means of curing or for preheating blanks to reduce the press cure time. 

Early generation RFID antennas were produced by chemically etching aluminum or copper foils and laminating them with polymer films ranging in thickness from 18-35 microns. However, today antennas are typically printed on polymer base substrates using conductive inks, an inexpensive and cost-effective way for different radio frequency waves to be received. Since the label typically requires opacity, a white carrier and facestock material, such as a paper stock, are used. An adhesive is applied to the carrier with a formulation designed to provide transportation-secure adhesion to the surface to which the RFID label is to be mounted. 

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