Abstract: A layered niobate which is used as a photocatalyst. The layered niobate has the formula [HaAb]+[Sr2Nb3O10]?. [Sr2Nb3O10]? forms main layers. [HaAb]+ forms interlayers, wherein H includes H+ and H3O+, A is K+, Cs+ and Rb+, 0.6?a?1, 0?b?0.4, and a+b=1. The layered niobate has different spacings between the main layers.

Abstract: A method is disclosed for attenuating ground roll in seismic data signals. Seismic data signals are obtained from nearby seismic sensors. A difference filter is created that incorporates an estimate of ground roll differential move-out between the seismic sensors. The difference filter is then applied to the seismic data signals to produce a ground roll attenuated seismic data signal. The method can be used with one-pass and multiple-pass filter operations and can be used in connection with pairs of seismic data signals or with groups of seismic data signals from an areal pattern of nearby seismic sensors. The seismic data signals may be appropriately pre-processed and factors in addition to the ground roll differential move-out can be incorporated when creating the difference filter. The inventive method can be implemented in the time domain or in the frequency domain.

Abstract: A procedure for surveying the seismic data of a region comprising a central body or structure, for instance an island, by means of a ship-towed streamer, wherein the ship follows a spiral path (2) around the central structure (1) to collected seismic data. Preferably the spiral is an Archimedean spiral with equidistant individual spiral line segments (7, 8, 9).

Abstract: A procedure for seismically surveying a region, in particular a marine region, wherein objects such as drilling platforms (1,2,3) prevent surveying by conventional seismic means such as towed streamers. In the invention, the total region first divided into sub-regions (5,6,7) wherein receiver chains (4) are stationarily mounted between two of the objects. A sound transmitter is the moved relative to the chain of receivers along a grid as the transmitter is repeatedly, periodically activated. Data collected by the receivers are recorded for each sub-region and the completely surveyed sub-regions are combined by grid transformation to construct a uniform three-dimensional data volume.