The structure, physicochemical properties and oxygen reduction abilities of carbons prepared by the carbonization of mixtures of ferrocene and poly(furfuryl alcohol) were studied. X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM) studies revealed that the carbons thus prepared consisted of two components; amorphous and turbostratic shell-like components. The fraction, f sharp , obtained by the analysis of the (002) peak in XRD was found to be a parameter that represented the degree of formation of the shell-like components. The formation of the shell-like components induced an increase in the mesopore volumes. Electrical conductivity increased exponentially with f sharp , which indicated that the conduction process was governed by a percolation process of the conductive shell-like components. The amount of CO-desorption by O 2 -TPD technique showed a maximum desorption at f sharp =0.3, and the further development in the sharp component led to a decrease in the CO-desorption. Mo¨ssbauer spectroscopy technique revealed the presence of a-Fe, c-Fe, Fe 1-x O and Fe 3 C in the prepared carbons, which were soluble species to acids. The oxygen reduction activity was studied in a oxygen saturated sulfuric acid solution by rotating disk electrode voltammetry. The oxygen reduction potential varied with f sharp ; initially it increased by f sharp =0.3 and then it decreased at higher f sharp values. This behavior was similar to that of CO-desorption, which meant the presence of an adequate degree of the development of the shell-like structure for maximizing oxygen adsorption. Removal of the surface metal component from the carbons by acidwashing resulted in no decrease in the oxygen reduction activities of the carbons. The nature of the active sites on the carbon materials is discussed.
Populations of blacklip abalone (Haliotis rubra) from southern Australia have been investigated genetically using protein gel electrophoresis. Allele frequency and genotype distributions were analysed to provide information on population structure, gene flow patterns and genetic differentiation among local populations. Breeding populations appear to be large. Measures of genetic distance reveal an 'isolation by distance' broad-scale population structure, although significant genetic heterogeneity can occur between sites < 3 km apart. Reasons for this apparent contradiction are discussed. It is concluded that zones of about 500 km of coastline, corresponding to 'neighbourhood size', could be recognized for the conservation of regional gene pools, but that stock-recruitment relationships need to be established on a localized basis.
Introduction of a national FSEP was associated with increased neonatal admissions but a reduction in intrapartum hypoxia, without increasing emergency caesarean section rates.
A B S T R A C T:M6ssbauer spectroscopy obtained with the sample at low temperatures and subject to large magnetic fields is discussed in terms of its use in analysing the naturally occurring polymorphs of FeOOH and the common growth precursor, ferrihydrite. Experiments on well-characterized synthetic samples provided benchmark results. A relatively simple means of quantitative analysis was used, in which sextets of Voigtian-shaped lines were summed and least-squares fitted. The results are discussed in terms of the magnetic structures of each compound.Fine-grained iron oxides and oxyhydroxides in soils and sediments can often be best identified using M6ssbauer spectroscopy, since their X-ray diffractograms are complicated by small crystallite size-broadening and the iron phases may constitute a relatively small proportion of the sample. Several excellent reviews of the work have been published
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