Typical microbial fuel cells (MFCs) rely on precious metals for reduction of oxygen at the cathode, but recently MFCs have been developed that use biocathodes for power generation with alternate electron acceptors. It is shown here that with illumination it is possible to develop a biocathode that uses dissolved carbon dioxide (bicarbonate) as the acceptor. During acclimation, the cathode was set at a potential of 0.242 V (vs. SHE) using a potentiostat. After approximately one month of acclimation, a current of 1 mA was sustained. Bicarbonate was reduced in stoichiometric agreement with current generation, with 0.28 +/- 0.02 moles of bicarbonate reduced per mole of electrons. When this biocathode was used in a two-bottle MFC, a power density of 750 mW m(-2) was produced. These results demonstrate that MFCs can be used to fix carbon dioxide as well as produce electricity

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Longitudinal and transverse giant magnetoimpedance ͑GMI͒ effects are studied in FeCuNbSiB and FeCuNbSiB/Cu/FeCuNbSiB films. In regard to as-deposited single layer films, hardly any GMI effect can be detected, while for as-deposited sandwiched films, the maximum GMI ratios of 32% and 11% are obtained in longitudinal and transverse fields, respectively. After annealing, the maximum GMI ratios of 18% and 14% are obtained for the single-layer films in longitudinal and transverse cases, while for the sandwiched films, the maximum GMI ratios are 67% and 80% in longitudinal and transverse cases, respectively. A giant magnetoinductance ratio as large as 1733% is obtained in annealed sandwiched films at a low frequency of 100 kHz. In order to know the relation between GMI effect and magnetic properties of the samples, the domain structures are observed by the Kerr effect.