Electronic tags

Polymer beads have also been tagged by treating them after each new diversity-introducing reaction with dye-containing, colloidal silica particles, which can be irreversibly adsorbed on the surface of the beads with the aid of polyelectrolytes such as poly(diallyldimethylammonium chloride) and poly(acrylic acid) [42,43]. Larger portions of support can also be linked to a chip that enables electronic tagging with a radio emitter [44-46]. 

Decode To "read" a chemical or electronic tag attached to a bead or mher solid support, for the purpose of determining the sci ucncc of reaction steps that were applied to the given head. This allows detcmtiniiig the eompoiiition of the. syiitlietic target on the bead. 

Positron emission tomography (PET) is an imaging technique that relies on the emission of positrons from radionucleotides tagged to an injectable compound of interest. Each positron emitted by the radioisotope collides with an electron to emit two photons at 180° from each other. The photons are detected and the data processed so that the source of the photons can be identified and an image generated showing the anatomical localization of the compound of interest. 

Detect 100% of photons Photon detected as a delta function Large number of pixels Time tag for each photon Measure photon wavelength Measure photon polarization No detector noise fr Up to 99% detected fr One electron for each photon fr Over 377 million pixels 0 No - framing detectors 0 No - provided by optics 0 No - provided by optics 0 Readout noise and dark current... 

It can be expected that, in the future, other organic electronic devices and circuits, such as sensors [72], radio-frequency identification tags (RFIDs) [73], and ring oscillators [74] may be fabricated using dissipative structures. 

We have studied demulsifier association by the electron spin resonance (ESR) technique. The spin label is covalently attached (Figure 5a) to the demulsifier. Normally, the ESR spectrum of a freely tumbling nitroxyl radical consists of three sharp peaks (Figure 5b). However, the spectrum for a tagged ethoxylated nonyl phenol resin (Figure 6a or 6b) shows only a single broad peak. 

Bacteria that live in the dark must derive the free energy to move electrons around in chemistry and a series of reactions based on the iron pyrite surfaces have been shown to be exoergic (Figure 9.13). The cationic pyrite surface serves as the catalyst for the binding of negatively charged species, perhaps tagged with... 

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