Sample irradiance

It is the preferred method where speed is not essential — but when the number of samples to be analyzed is large, multiple sample irradiation on the lucite wheel. with single-axis rotation is used. The precision of this latter technique for six plant samples of Octol is shown in Table 2a. 

EDS compositional analysis with a focused 2nm electron beam of the FEG-TEM in the central part of mother cluster on the Ar-irradiated AuAg sample, gives an Au/ Ag ratio (measured at AuL and AgL) of 1.4 + 0.1, whereas the same ratio measured on the satellite clusters is 2.3+0.8. Similar ratios have been found from EDS analysis on AuAg sample irradiated with He, Ne, or Kr ions. EDS analysis reveals therefore a preferential extraction of Au atoms from the original cluster and this selective dealloying process is independent of the particular system investigated (we obtained similar results for Ne-irradiated AuCu cluster, as previously reported). 

The proton experiment is a so-called single channel experiment the same channel is used for sample irradiation and observation of the signal, and the irradiation frequency is set (automatically) to the resonance frequency of the protons at the magnetic field strength used by the spectrometer. 

Figure k. Total chromosome type aberration frequencies (sum of dicentrics, rings, terminal, and interstitial deletions) of in vitro blood samples, irradiated with Rn-222 decay products. 

The temperature dependence of luminescence from the sample irradiated at 1 x 1013 cm-2 with 28Si+ indicates, above —110 K, an activation energy of 90 meV for the competing nonradiative recombination process— this competing process may be the thermal dissociation of geminate pairs or bound excitons at donorlike or acceptorlike centers. The 0.09-eV value of activation energy is consistent with the results of Troxell and Watkins (1979). 

Figure 4. The elastic (G ) and viscous modulus (G") at the gel point match well for samples irradiated by using the pulse or continuous modes.

Figure 4. Results from measurements of10Be/9Be ratios in BeO samples irradiated...

Fig. 8.8. Experiment set-up and obtained results. Counter-clockwise, from top left schematic view of the set-up for the activation experiment, accelerated electron spectrum as measured by a magnetic spectrometer, full differential cross section for the reaction 197Au(7, n)196Au (dotted) and bremsstrahlung spectrum reconstructed after the deconvolution calculations (solid), x-ray emission spectrum of 196Au measured after the gold sample irradiation...

Although quantification of the elements present in the y spectrum can in theory be achieved from first principles using the equation given above, in practice uncertainties in the neutron capture cross-section and variations in the neutron flux within the reactor mean that it is better to use standards. These standards must be included in each batch of samples irradiated in order to account for variations in neutron flux inside the reactor. For analysis of minor and trace elements calibration is easier than with other analytical methods provided that the major element composition remains reasonably constant, as the y ray intensity is proportional to concentration over a very wide range of concentrations. However, for analysis of major elements, e.g., silver in silver coins, the relationship between intensity and concentration is more complex, due to progressive absorption of neutrons as they pass through the specimen. In such cases y ray intensity will also depend on the thickness of the sample and therefore specialized calibration methods are required (Tite 1972 277). 

Steady-State ESR Spectroscopy. In this method, the ESR spectrum is monitored, usually with constant sample irradiation. Radical concentrations reach a steady state, and the rate constants for termination can be determined from the radical concentrations if the rate constants for radical formation are known. Estimates of the rate of formation of radicals are often a source of large errors. The technique often is applied at low temperatures so that diffusion is slowed and adequate radical concentrations are achieved, and extrapolation of the results to ambient temperatures can give large errors. 

Polymerization of fullerite was first obtained at ambient pressure by means of sample irradiation [456]. Visible or UV light leads molecules to link together in a covalently bonded fee structure. From x-ray diffraction data a 2 + 2 cycloaddition mechanism was proposed in which the van der Waals interactions are replaced by single covalent bonds between adjacent Ceo molecules [456]. More recent results indicate that linear chains with two square rings per molecule or branched chains with three square rings per molecule are obtained... 

The yield of strand breaks appears to be relatively independent of sample irradiation temperature, as discussed above. This implies that competing processes do not have much impact on reactions 1,2, 5, and 8. That is, the competitions between holes tunneling from the solvent to DNA and deprotonation of HsO " and between hole tunneling form the sugar phosphate to the bases and deprotonation of the sugar are fairly temperature-insensitive (from 4 to 300 K). In contrast, the mobility of the holes and excess electrons centered on the bases is very temperature-sensitive, zero at 4 K, onset at —40 K, and highly mobile at 180 K. By our model, the mobility is controlled by the proton transfer... 

Figure 18 Comparison of optical absorption data and TEM images (at the same magnification) for two gold samples irradiated by laser pulses having the same fluence (0.25 J cm ) and different pulse width. Top with a 7-nsec laser pulse at 800 nm. (a) Partial melting of the gold nanorods and (b) selective optical hole burning in the near-IR band corresponding to the nanorods. Bottom with laser pulses of 100 fsec. (c) Complete melting of the gold nanorods into nanodots and (d) complete depletion of the nanorod band. (From Ref 211.)...

Figure 13 Dependence on 10-MeV-proton and 1-MeV-electron fluence of the remaining factor of short circuit current (Isc) for Si-BSFR solar cells. Circles and squares represent the results for samples irradiated with 10-MeV protons and 1-MeV electrons, respectively. Broken lines represent the fitting results based on a model mentioned in the text.

In addition to SiC/SiC, irradiation effects on insulators such as AI2O3 were also examined [70]. As a result, synergistic effects such as the diffusion of H and the growth of cavities were observed in samples irradiated with triple beams. As for carbon fiber composites, the microhardness increased by triple-beam irradiation [71], which was a different result from that obtained from 14-MeV neutron irradiation (8 x lO n/cm ) experiment. 

Fig. 1.6 Photocatalytic kiUing of . coli on TiO electrosprayed samples (a - fabric and b - aluminum foil) in comparison with uncoated (control) samples irradiated with UV-A light...

Figure 6.4 shows the relaxation function i/)(t) of irradiated As Scioo-x alloy films, determined as follows. The sample irradiated with light of photon energy hv > opt... 

We did not measure a mixture of the Phillips experimental polymer with Surlyn A itself since phase contrast microscopy indicated that the former had segregated as a separate crystalline phase. However, the differential absorbance at 10.35 microns of a Surlyn A sample irradiated to a 50-megarad dose decreased only 6.0% after sample and reference were exposed to HC1 for 2 weeks. Furthermore, the rate of trans-v inylene growth with dose in Surlyn A was sensiblv unaffected by prior exposure to HC1. 

Cellobiose Octaacetate and Glucose Pentaacetate. The results on both compounds were similar. Samples irradiated at 253.7 and 313 mfi, both in the presence of oxygen and in vacuum, were saponified. Infrared analysis of the saponified residues showed that all samples had carbonyl absorption at 5.76 to 5.78 microns, owing to lactones, ketones,... 

At low temperatures oils autooxidize slightly more than corresponding samples irradiated at room temperature. These peroxide values continue... 

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