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symbol for the element rutherfordiumrutherfordium
, artificially produced radioactive chemical element; symbol Rf; at. no. 104; mass number of most stable isotope 265; m.p., b.p., and sp. gr. unknown; valence +4.
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On drawings, abbr. for roof.


(Radio Frequency) The range of electromagnetic frequencies above the audio range and below infrared light (from 10 kHz to 300 GHz). RF transmission includes AM and FM radio, analog and digital TV, satellite communications, cordless phones, cellular and Wi-Fi. Signals can be focused in one direction (directional), or they can transmit in all directions (omnidirectional).

Frequency and Power
The range of frequencies and power output determine how well RF signals can penetrate objects. Signals up to 5 GHz can generally transmit through wooden and plaster walls in their path, but the higher the frequency, the more an unobstructed view from transmitter to receiver is required. See line of sight, RF modulation, RF shielding, RF remote control, microwave and ISM band.

RF Ports
Radio frequency ports (right) are typically coaxial cable connectors for antennas and TVs. See coaxial cable.
References in periodicals archive ?
The pigment fractions of P purpurogenum were separated in to 3 bands (pinkish red, orange and yellow) whose Rf values and [e.
If the two substances have the same Rf values, they are likely, but not necessarily, the same compound.
Limitation like closeness of Rf values of cineole and eugenol is overcome by the use of HPTLC method instead of HPLC.
In the samples studied, Rf value of THC-COOH in some of the samples varied between 0.
This shows average RF values outside the upper and lower resistance limits of the progenitors, suggesting the occurrence of an additional gene involved in the determination of resistance or presence of epistasis.
In vegetable gardens, several species showed similar RF values and weeds with the highest values were C.
Protein markers with molecular weights log molecular weights and Rf values are shown in table (01).
Regression analysis showed a statistically not significant relationship between the RF values for topical application and for exposure to films on filter paper (P > 0.
The SAS Proc Mixed procedure for repeated measures computed maximum likelihood estimates of factors potentially influencing RF values as fixed effects (shielding, distance, elevation, percentage of transmitters visible) along with "day" in the statistical model using an unstructured covariance matrix.
After 30 min of contact the TLC-plate was removed and after 24 h of incubation at 37[degrees]C the areas of antimicrobial activity could be observed and the Rf values of the antimicrobial compounds determined.
The TLC separation of UV 366 shows several compounds but not all show similar Rf values as the antimicrobial active compounds (Results on Rf values not shown).