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Free radical spatial distribution

Ward JF (1981) Some biochemical consequences of the spatial distribution of ionizing radiation-produced free radicals. Radiat Res 86 185-195 Ward JF (1985) Biochemistry of DNA lesions. Radiat Res 104 103-111... [Pg.479]

PEDRI (also known as Overhauser MRI) integrates the principles of Overhauser DNP with MRI to provide information on the spatial distribution of free radicals within the system of interest. Much work has been done to... [Pg.117]

Ground-based mm-wave emission techniques have recently provided definitive identification of HO2 in the upper stratosphere, measurements which can be directly compared with previous in situ experiments [13]. Figure 8 presents those recent spectra. These observations can be used both to cross check in situ techniques, for which two have been reported, and to extend measurements of this key free radical above the maximum altitude attainable by balloons, specifically above 45 km. We thus find a critical combination of independent techniques with highly complementary temporal and spatial coverage evolving such that the vertical distribution of a key free radical will soon be established in the scientific literature. [Pg.357]

Using a simplified representation of centroid of charge distributions, one obtains the pictures collected in Table V, for a series of model free radicals. When two centroids of different types (a and /3) are near one to the other, we adopt the Linnett notation, i.e., a line, but we do not distinguish between spatial and nonspatial pairs. Moreover, centroids of the CH, NH, or OH bond are not always indicated. [Pg.24]

Although the reasons underlying this spatial relationship are not known, its existence is additional evidence for conformation as a significant factor in determining the free radical distribution. [Pg.519]

Synthetic polymer systems can exhibit feedback through several mechanisms. The simplest is thermal autocatalysis, which occurs in any exothermic reaction. The reaction raises the temperature of the system, which increases the rate of reaction through the Arrhenius dependence of the rate constants. In a spatially distributed system, this mechanism allows propagation of thermal fronts. Free-radical polymerizations are highly exothermic. [Pg.10]

An open volume, high isolation RF system suitable for pulsed NMR and EPR spectrometers with reduced dead time has been described. It comprises a set of three RF surface coils disposed with mutually parallel RF fields and a double-channel receiver (RX). Theoretical and experimental results obtained with a prototype operating at about 100 MHz have been reported. Each surface RF coil (diameter 5.5 cm) was tuned to 100.00 0.01 MHz when isolated. Because of the mutual coupling and the geometry of the RF coils, only two resonances at 97.94 MHz and 101.85 MHz were observed. These were associated with two different RF field spatial distributions. In continuous mode operation the isolation between the TX coil and one of the RX coils (singlechannel) was about —10 dB. By setting the double-channel RF assembly in subtraction mode the isolation values were optimised to about —75 dB. The described system was selected as a model for potential applications in solid-state NMR and in free radical EPR spectroscopy and imaging. [Pg.278]


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See also in sourсe #XX -- [ Pg.13 , Pg.20 , Pg.30 ]




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Free distribution

Free-radical distributions

Spatial distributions

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